House Committees' Authority to Investigate for Impeachment ( 2020 )


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  • (Slip Opinion)
    House Committees’ Authority to
    Investigate for Impeachment
    The House of Representatives must expressly authorize a committee to conduct an
    impeachment investigation and to use compulsory process in that investigation before
    the committee may compel the production of documents or testimony in support of the
    House’s power of impeachment.
    The House had not authorized an impeachment investigation in connection with
    impeachment-related subpoenas issued by House committees before October 31, 2019,
    and the subpoenas therefore had no compulsory effect.
    The House’s adoption of Resolution 660 on October 31, 2019, did not alter the legal
    status of those subpoenas, because the resolution did not ratify or otherwise address
    their terms.
    January 19, 2020
    MEMORANDUM OPINION FOR THE COUNSEL TO THE PRESIDENT
    On September 24, 2019, Speaker of the House Nancy Pelosi “an-
    nounc[ed]” at a press conference that “the House of Representatives is
    moving forward with an official impeachment inquiry” into the Presi-
    dent’s actions and that she was “directing . . . six Committees to proceed
    with” several previously pending “investigations under that umbrella of
    impeachment inquiry.” 1 Shortly thereafter, the House Committee on
    Foreign Affairs issued a subpoena directing the Secretary of State to
    produce a series of documents related to the recent conduct of diplomacy
    between the United States and Ukraine. See Subpoena of the Committee
    on Foreign Affairs (Sept. 27, 2019). In an accompanying letter, three
    committee chairmen stated that their committees jointly sought these
    documents, not in connection with legislative oversight, but “[p]ursuant to
    the House of Representatives’ impeachment inquiry.” 2 In the following
    days, the committees issued subpoenas to the Acting White House Chief
    1 Nancy Pelosi, Speaker of the House, Press Release: Pelosi Remarks Announcing
    Impeachment Inquiry (Sept. 24, 2019), www.speaker.gov/newsroom/92419-0 (“Pelosi
    Press Release”).
    2 Letter for Michael R. Pompeo, Secretary of State, from Eliot L. Engel, Chairman,
    Committee on Foreign Affairs, U.S. House of Representatives, Adam Schiff, Chairman,
    Permanent Select Committee on Intelligence, U.S. House of Representatives, and Elijah
    E. Cummings, Chairman, Committee on Oversight & Reform, U.S. House of Representa-
    tives at 1 (Sept. 27, 2019) (“Three Chairmen’s Letter”).
    1
    Opinions of the Office of Legal Counsel in Volume 44
    of Staff, the Secretary of Defense, the Secretary of Energy, and several
    others within the Executive Branch.
    Upon the issuance of these subpoenas, you asked whether these com-
    mittees could compel the production of documents and testimony in
    furtherance of an asserted impeachment inquiry. We advised that the
    committees lacked such authority because, at the time the subpoenas were
    issued, the House had not adopted any resolution authorizing the commit-
    tees to conduct an impeachment inquiry. The Constitution vests the “sole
    Power of Impeachment” in the House of Representatives. U.S. Const.
    art. I, § 2, cl. 5. For precisely that reason, the House itself must authorize
    an impeachment inquiry, as it has done in virtually every prior impeach-
    ment investigation in our Nation’s history, including every one involving
    a President. A congressional committee’s “right to exact testimony and to
    call for the production of documents” is limited by the “controlling char-
    ter” the committee has received from the House. United States v. Rumely,
    
    345 U.S. 41
    , 44 (1953). Yet the House, by its rules, has authorized its
    committees to issue subpoenas only for matters within their legislative
    jurisdiction. Accordingly, no committee may undertake the momentous
    move from legislative oversight to impeachment without a delegation by
    the full House of such authority.
    We are not the first to reach this conclusion. This was the position of
    the House in the impeachments of Presidents Nixon and Clinton. In the
    case of President Nixon, following a preliminary inquiry, the House
    adopted a formal resolution as a “necessary step” to confer the “investiga-
    tive powers” of the House “to their full extent” upon the Judiciary Com-
    mittee. 120 Cong. Rec. 2350–51 (1974) (statement of Rep. Rodino); see
    H.R. Res. 803, 93d Cong. (1974). As the House Parliamentarian ex-
    plained, it had been “considered necessary for the House to specifically
    vest the Committee on the Judiciary with the investigatory and subpena
    power to conduct the impeachment investigation.” 3 Lewis Deschler,
    Deschler’s Precedents of the United States House of Representatives ch.
    14, § 15.2, at 2172 (1994) (Parliamentarian’s Note). 3 The House followed
    the same course in the impeachment of President Clinton. After reviewing
    the Independent Counsel’s referral, the Judiciary Committee “decided that
    it must receive authorization from the full House before proceeding on
    3 Although volume 3 of Deschler’s Precedents was published in 1979, our citations of
    Deschler’s Precedents use the continuously paginated version that is available at www.
    govinfo.gov/collection/precedents-of-the-house.
    2
    House Committees’ Authority to Investigate for Impeachment
    any further course of action.” H.R. Rep. No. 105-795, at 24 (1998). The
    House again adopted a resolution authorizing the committee to issue
    compulsory process in support of an impeachment investigation. See H.R.
    Res. 581, 105th Cong. (1998). As Representative John Conyers summa-
    rized in 2016: “According to parliamentarians of the House past and
    present, the impeachment process does not begin until the House actually
    votes to authorize [a] Committee to investigate the charges.” 4
    In marked contrast with these historical precedents, in the weeks after
    the Speaker’s announcement, House committees issued subpoenas without
    any House vote authorizing them to exercise the House’s authority under
    the Impeachment Clause. The three committees justified the subpoenas
    based upon the Rules of the House, which authorize subpoenas for matters
    within a committee’s jurisdiction. But the Rules assign only “legislative
    jurisdiction[]” and “oversight responsibilities” to the committees. H.R.
    Rules, 116th Cong., Rule X, cl. 1 (Jan. 11, 2019) (“Committees and their
    legislative jurisdictions”), cl. 2 (“General oversight responsibilities”); see
    also H.R. Rule X, cls. 3(m), 11. The House’s legislative power is distinct
    from its impeachment power. Compare U.S. Const. art. I, § 1, with 
    id. art. I,
    § 2, cl. 5. Although committees had that same delegation during the
    Clinton impeachment and a materially similar one during the Nixon
    impeachment, the House determined on both occasions that the Judiciary
    Committee required a resolution to investigate. Speaker Pelosi purported
    to direct the committees to conduct an “official impeachment inquiry,”
    but the House Rules do not give the Speaker any authority to delegate
    investigative power. The committees thus had no delegation authorizing
    them to issue subpoenas pursuant to the House’s impeachment power.
    In the face of objections to the validity of the committee subpoenas that
    were expressed by the Administration, by ranking minority members in
    the House, and by many Senators, among others, on October 31, 2019, the
    House adopted Resolution 660, which “directed” six committees “to
    continue their ongoing investigations” as part of the “existing House of
    Representatives inquiry into whether sufficient grounds exist” to impeach
    President Trump. H.R. Res. 660, 116th Cong. § 1 (2019). Resolution
    660’s direction, however, was entirely prospective. The resolution did not
    purport to ratify any previously issued subpoenas or even make any men-
    4 Impeachment Articles Referred on John Koskinen (Part III): Hearing Before the H.
    Comm. on the Judiciary, 114th Cong. 3 (2016).
    3
    Opinions of the Office of Legal Counsel in Volume 44
    tion of them. Accordingly, the pre-October 31 subpoenas, which had not
    been authorized by the House, continued to lack compulsory force. 5
    I.
    Since the start of the 116th Congress, some members of Congress have
    proposed that the House investigate and impeach President Trump. On
    January 3, 2019, the first day of the new Congress, Representative Brad
    Sherman introduced a resolution to impeach “Donald John Trump, Presi-
    dent of the United States, for high crimes and misdemeanors.” H.R. Res.
    13, 116th Cong. (2019). The Sherman resolution called for impeachment
    based upon the President’s firing of the Director of the Federal Bureau of
    Investigation, James Comey. See 
    id. Consistent with
    settled practice, the
    resolution was referred to the Judiciary Committee. See H.R. Doc. No.
    115-177, Jefferson’s Manual § 605, at 324 (2019).
    The Judiciary Committee did not act on the Sherman resolution, but it
    soon began an oversight investigation into related subjects that were also
    the focus of a Department of Justice investigation by Special Counsel
    Robert S. Mueller, III. On March 4, 2019, the committee served document
    requests on the White House and 80 other agencies, entities, and individu-
    als, “unveil[ing] an investigation . . . into the alleged obstruction of jus-
    tice, public corruption, and other abuses of power by President Trump, his
    associates, and members of his Administration.” 6 Those document re-
    quests did not mention impeachment.
    After the Special Counsel finished his investigation, the Judiciary
    Committee demanded his investigative files, describing its request as an
    5 This opinion memorializes the advice we gave about subpoenas issued before Octo-
    ber 31. We separately addressed some subpoenas issued after that date. See, e.g., Letter
    for Pat A. Cipollone, Counsel to the President, from Steven A. Engel, Assistant Attorney
    General, Office of Legal Counsel (Nov. 7, 2019) (subpoena to Mick Mulvaney); Letter for
    Pat A. Cipollone, Counsel to the President, from Steven A. Engel, Assistant Attorney
    General, Office of Legal Counsel (Nov. 3, 2019) (subpoena to John Eisenberg); Exclusion
    of Agency Counsel from Congressional Depositions in the Impeachment Context, 43 Op.
    O.L.C. __ (Nov. 1, 2019).
    6 U.S. House of Representatives Committee on the Judiciary, Press Release: House
    Judiciary Committee Unveils Investigation into Threats Against the Rule of Law (Mar. 4,
    2019), judiciary.house.gov/news/press-releases/house-judiciary-committee-unveils-
    investigation-threats-against-rule-law; see also Letter for the White House, c/o Pat
    Cipollone, from Jerrold Nadler, Chairman, Committee on the Judiciary, U.S. House of
    Representatives (Mar. 4, 2019).
    4
    House Committees’ Authority to Investigate for Impeachment
    exercise of legislative oversight authority. See Letter for William P. Barr,
    Attorney General, from Jerrold Nadler, Chairman, Committee on the
    Judiciary, U.S. House of Representatives at 3 (May 3, 2019) (asserting
    that “[t]he Committee has ample jurisdiction under House Rule X(l ) to
    conduct oversight of the Department [of Justice], undertake necessary
    investigations, and consider legislation regarding the federal obstruction
    of justice statutes, campaign-related crimes, and special counsel investiga-
    tions, among other things”). The committee’s subsequent letters and
    public statements likewise described its inquiry as serving a “legislative
    purpose.” E.g., Letter for Pat Cipollone, White House Counsel, from
    Jerrold Nadler, Chairman, Committee on the Judiciary, U.S. House of
    Representatives at 3–6 (May 16, 2019) (describing the “legislative pur-
    pose of the Committee’s investigation” (capitalization altered)).
    Over time, the Judiciary Committee expanded the description of its in-
    vestigation to claim that it was considering impeachment. The committee
    first mentioned impeachment in a May 8, 2019 report recommending that
    the Attorney General be held in contempt of Congress. In a section enti-
    tled “Authority and Legislative Purpose,” the committee stated that one
    purpose of the inquiry was to determine “whether to approve articles of
    impeachment with respect to the President or any other Administration
    official.” H.R. Rep. No. 116-105, at 12, 13 (2019). 7
    The committee formally claimed to be investigating impeachment when
    it petitioned the U.S. District Court for the District of Columbia to release
    grand-jury information related to the Special Counsel’s investigation. See
    Application at 1–2, In re Application of the Comm. on the Judiciary, U.S.
    7 On June 11, 2019, the full House adopted Resolution 430. Its first two clauses author-
    ized the Judiciary Committee to file a lawsuit to enforce subpoenas against Attorney
    General William Barr and former White House Counsel Donald McGahn and purported to
    authorize the Bipartisan Legal Advisory Group to approve future litigation. See H.R. Res.
    430, 116th Cong. (2019). The next clause of the resolution then stated that, “in connection
    with any judicial proceeding brought under the first or second resolving clauses, the chair
    of any standing or permanent select committee exercising authority thereunder has any
    and all necessary authority under Article I of the Constitution.” 
    Id. The resolution
    did not
    mention “impeachment” and, by its terms, authorized actions only in connection with the
    litigation authorized “under the first or second resolving clauses.” On the same day that
    the House adopted Resolution 430, Speaker Pelosi stated that the House’s Democratic
    caucus was “not even close” to an impeachment inquiry. Rep. Nancy Pelosi (D-CA)
    Continues Resisting Impeachment Inquiry, CNN (June 11, 2019), transcripts.cnn.com/
    TRANSCRIPTS/1906/11/cnr.04.html.
    5
    Opinions of the Office of Legal Counsel in Volume 44
    House of Reps., No. 19-gj-48 (D.D.C. July 26, 2019); see also Memoran-
    dum for Members of the Committee on the Judiciary from Jerrold Nadler,
    Chairman, Re: Lessons from the Mueller Report, Part III: “Constitutional
    Processes for Addressing Presidential Misconduct” at 3 (July 11, 2019)
    (advising that the Committee would seek documents and testimony “to
    determine whether the Committee should recommend articles of im-
    peachment against the President or any other Article I remedies, and if so,
    in what form”). 8 The committee advanced the same contention when
    asking the district court to compel testimony before the committee by
    former White House Counsel Donald McGahn. See Compl. for Declarato-
    ry and Injunctive Relief ¶ 1, Comm. on the Judiciary, U.S. House of Reps.
    v. McGahn, No. 19-cv-2379 (D.D.C. Aug. 7, 2019) (contending that the
    Judiciary Committee was “now determining whether to recommend
    articles of impeachment against the President based on the obstructive
    conduct described by the Special Counsel”).
    In connection with this litigation, Chairman Nadler described the com-
    mittee as conducting “formal impeachment proceedings.” David Priess &
    Margaret Taylor, What if the House Held Impeachment Proceedings and
    Nobody Noticed?, Lawfare (Aug. 12, 2019), www.lawfareblog.com/what-
    if-house-held-impeachment-proceedings-and-nobody-noticed (chronicling
    the evolution in Chairman Nadler’s descriptions of the investigation).
    Those assertions coincided with media reports that Chairman Nadler had
    privately asked Speaker Pelosi to support the opening of an impeachment
    inquiry. See, e.g., Andrew Desiderio, Nadler: ‘This is Formal Impeach-
    ment Proceedings,’ Politico (Aug. 8, 2019), www.politico.com/story/
    2019/08/08/nadler-this-is-formal-impeachment-proceedings-1454360
    (noting that Nadler “has privately pushed Speaker Nancy Pelosi to support
    a formal inquiry of whether to remove the president from office”). On
    September 12, the Judiciary Committee approved a resolution describing
    its investigation as an impeachment inquiry and adopting certain proce-
    dures for the investigation. See Resolution for Investigative Procedures
    Offered by Chairman Jerrold Nadler, H. Comm. on the Judiciary, 116th
    8 While the House has delegated to the Bipartisan Legal Advisory Group the ability to
    “articulate[] the institutional position of ” the House, it has done so only for purposes of
    “litigation matters.” H.R. Rule II, cl. 8(b). Therefore, neither the group, nor the House
    counsel implementing that group’s directions, could assert the House’s authority in
    connection with an impeachment investigation, which is not a litigation matter.
    6
    House Committees’ Authority to Investigate for Impeachment
    Cong. (Sept. 12, 2019), docs.house.gov/meetings/JU/JU00/20190912/
    109921/BILLS-116pih-ResolutionforInvestigativeProcedures.pdf.
    Speaker Pelosi did not endorse the Judiciary Committee’s characteriza-
    tion of its investigation during the summer of 2019. But she later purport-
    ed to announce a formal impeachment inquiry in connection with a sepa-
    rate matter arising out of a complaint filed with the Inspector General of
    the Intelligence Community. The complaint, cast in the form of an un-
    signed letter to the congressional intelligence committees, alleged that, in
    a July 25, 2019 telephone call, the President sought to pressure Ukrainian
    President Volodymyr Zelenskyy to investigate the prior activities of one
    of the President’s potential political rivals. See Letter for Richard Burr,
    Chairman, Select Committee on Intelligence, U.S. Senate, and Adam
    Schiff, Chairman, Permanent Select Committee on Intelligence, U.S.
    House of Representatives at 2–3 (Aug. 12, 2019). After the Inspector
    General reported the existence of the complaint to the intelligence com-
    mittees, the President declassified the official record of the July 25 tele-
    phone call and the complaint, and they were publicly released on Septem-
    ber 25 and 26, respectively.
    On September 24, the day before the release of the call record, Speaker
    Pelosi “announc[ed]” that “the House of Representatives is moving for-
    ward with an official impeachment inquiry” and that she was “direct[ing]
    . . . six [c]ommittees to proceed with their investigations under that um-
    brella of impeachment inquiry.” Pelosi Press Release, supra note 1. In an
    October 8, 2019 court hearing, the House’s General Counsel invoked the
    Speaker’s announcement as purportedly conclusive proof that the House
    had opened an impeachment inquiry. Tr. of Mot. Hrg. at 23, In re Appli-
    cation of the Comm. on the Judiciary (“We are in an impeachment in-
    quiry, an impeachment investigation, a formal impeachment investigation
    because the House says it is. The speaker of the House has specifically
    said that it is.”).
    On September 27, Chairman Engel of the Foreign Affairs Committee
    issued a subpoena to Secretary of State Pompeo “[p]ursuant to the House
    of Representatives’ impeachment inquiry.” Three Chairmen’s Letter,
    supra note 2, at 1. That subpoena was the first to rely on the newly pro-
    claimed “impeachment inquiry.” A number of subpoenas followed, each
    of which was accompanied by a letter signed by the chairmen of three
    committees (Foreign Affairs, Oversight and Reform, and the Permanent
    Select Committee on Intelligence (“HPSCI”)). Although the September 27
    letter mentioned only the “impeachment inquiry” as a basis for the ac-
    7
    Opinions of the Office of Legal Counsel in Volume 44
    companying subpoena, subsequent letters claimed that other subpoenas
    were issued both “[p]ursuant to the House of Representatives’ impeach-
    ment inquiry” and “in exercise of ” the committees’ “oversight and legis-
    lative jurisdiction.” 9
    Following service of these subpoenas, you and other officials within the
    Executive Branch requested our advice with respect to the obligations of
    the subpoenas’ recipients. We advised that the subpoenas were invalid
    because, among other reasons, the committees lacked the authority to
    conduct the purported inquiry and, with respect to several testimonial
    subpoenas, the committees impermissibly sought to exclude agency
    counsel from scheduled depositions. In reliance upon that advice, you and
    other responsible officials directed employees within their respective
    departments and agencies not to provide the documents and testimony
    requested under those subpoenas.
    On October 8, 2019, you sent a letter to Speaker Pelosi and the three
    chairmen advising them that their purported impeachment inquiry was
    “constitutionally invalid” because the House had not authorized it. 10 The
    House Minority Leader, Kevin McCarthy, and the Ranking Member of the
    Judiciary Committee, Doug Collins, had already made the same objec-
    9 E.g., Letter for John Michael Mulvaney, Acting Chief of Staff to the President, from
    Elijah E. Cummings, Chairman, Committee on Oversight & Reform, U.S. House of
    Representatives, Adam B. Schiff, Chairman, Permanent Select Committee on Intelligence,
    U.S. House of Representatives, and Eliot L. Engel, Chairman, Committee on Foreign
    Affairs, U.S. House of Representatives at 1 (Oct. 4, 2019); Letter for Mark T. Esper,
    Secretary of Defense, from Adam B. Schiff, Chairman, Permanent Select Committee on
    Intelligence, U.S. House of Representatives, Eliot L. Engel, Chairman, Committee on
    Foreign Affairs, U.S. House of Representatives, and Elijah E. Cummings, Chairman,
    Committee on Oversight & Reform, U.S. House of Representatives at 1 (Oct. 7, 2019);
    Letter for Gordon Sondland, U.S. Ambassador to the European Union, from Adam B.
    Schiff, Chairman, Permanent Select Committee on Intelligence, U.S. House of Represent-
    atives, Elijah E. Cummings, Chairman, Committee on Oversight & Reform, U.S. House
    of Representatives, and Eliot L. Engel, Chairman, Committee on Foreign Affairs, U.S.
    House of Representatives at 1 (Oct. 8, 2019); Letter for James Richard “Rick” Perry,
    Secretary of Energy, from Eliot L. Engel, Chairman, Committee on Foreign Affairs, U.S.
    House of Representatives, Adam B. Schiff, Chairman, Permanent Select Committee on
    Intelligence, U.S. House of Representatives, and Elijah E. Cummings, Chairman, Com-
    mittee on Oversight & Reform, U.S. House of Representatives at 1 (Oct. 10, 2019).
    10 Letter for Nancy Pelosi, Speaker, U.S. House of Representatives, et al., from Pat A.
    Cipollone, Counsel to the President at 2–3 (Oct. 8, 2019).
    8
    House Committees’ Authority to Investigate for Impeachment
    tion. 11 Senator Lindsey Graham introduced a resolution in the Senate, co-
    sponsored by 49 other Senators, which objected to the House’s impeach-
    ment process because it had not been authorized by the full House and did
    not provide the President with the procedural protections enjoyed in past
    impeachment inquiries. S. Res. 378, 116th Cong. (2019).
    On October 25, 2019, the U.S. District Court for the District of Colum-
    bia granted the Judiciary Committee’s request for grand-jury information
    from the Special Counsel’s investigation, holding that the committee
    was conducting an impeachment inquiry that was “preliminar[y] to . . . a
    judicial proceeding,” for purposes of the exception to grand-jury secrecy
    in Rule 6(e)(3)(E)(i) of the Federal Rules of Criminal Procedure. See In re
    Application of the Comm. on the Judiciary, U.S. House of Reps., No. 19-
    gj-48, 
    2019 WL 5485221
    (D.D.C. Oct. 25, 2019), stay granted, No. 19-
    5288 (D.C. Cir. Oct. 29, 2019), argued (D.C. Cir. Jan. 3, 2020). In so
    holding, the court concluded that the House need not adopt a resolution
    before a committee may begin an impeachment inquiry. 
    Id. at *26–28.
    As
    we discuss below, the district court’s analysis of this point relied on a
    misreading of the historical record.
    Faced with continuing objections from the Administration and mem-
    bers of Congress to the validity of the impeachment-related subpoenas,
    the House decided to take a formal vote to authorize the impeachment
    inquiry. See Letter for Democratic Members of the House from Nancy
    Pelosi, Speaker of the House (Oct. 28, 2019). On October 31, the House
    adopted a resolution “direct[ing]” several committees “to continue their
    ongoing investigations as part of the existing House of Representatives
    inquiry into whether sufficient grounds exist for the House of Representa-
    tives to exercise its Constitutional power to impeach Donald John Trump,
    President of the United States of America.” Resolution 660, § 1. The
    resolution also adopted special procedures for impeachment proceedings
    before HPSCI and the Judiciary Committee.
    11 See Letter for Nancy Pelosi, Speaker, U.S. House of Representatives, from Kevin
    McCarthy, Republican Leader, U.S. House of Representatives at 1 & n.1 (Oct. 3, 2019);
    Mem. Amicus Curiae of Ranking Member Doug Collins in Support of Denial at 5–21, In
    re Application of the Comm. on the Judiciary (D.D.C. Oct. 3, 2019).
    9
    Opinions of the Office of Legal Counsel in Volume 44
    II.
    The Constitution vests in the House of Representatives a share of Con-
    gress’s legislative power and, separately, “the sole Power of Impeach-
    ment.” U.S. Const. art. I, § 1; 
    id. art. I,
    § 2, cl. 5. Both the legislative
    power and the impeachment power include an implied authority to inves-
    tigate, including by means of compulsory process. But those investigative
    powers are not interchangeable. The House has broadly delegated to
    committees its power to investigate for legislative purposes, but it has
    held impeachment authority more closely, granting authority to conduct
    particular impeachment investigations only as the need has arisen. The
    House has followed that approach from the very first impeachment in-
    quiry through dozens more that have followed over the past 200 years,
    including every inquiry involving a President.
    In so doing, the House has recognized the fundamental difference be-
    tween a legislative oversight investigation and an impeachment investiga-
    tion. The House does more than simply pick a label when it “debate[s]
    and decide[s] when it wishes to shift from legislating to impeaching” and
    to authorize a committee to take responsibility for “the grave and weighty
    process of impeachment.” Trump v. Mazars USA, LLP, 
    940 F.3d 710
    , 737,
    738 (D.C. Cir. 2019), cert. granted, No. 19-715 (Dec. 13, 2019); see also
    
    id. at 757
    (Rao, J., dissenting) (recognizing that “the Constitution forces
    the House to take accountability for its actions when investigating the
    President’s misconduct”). Because a legislative investigation seeks “in-
    formation respecting the conditions which the legislation is intended to
    affect or change,” McGrain v. Daugherty, 
    273 U.S. 135
    , 175 (1927),
    “legislative judgments normally depend more on the predicted conse-
    quences of proposed legislative actions and their political acceptability,
    than on precise reconstruction of past events,” Senate Select Comm. on
    Presidential Campaign Activities v. Nixon, 
    498 F.2d 725
    , 732 (D.C. Cir.
    1974) (en banc). By contrast, an impeachment inquiry must evaluate
    whether a civil officer did, or did not, commit treason, bribery, or another
    high crime or misdemeanor, U.S. Const. art. II, § 4, and it is more likely
    than a legislative oversight investigation to call for the reconstruction of
    past events.
    Thus, the House has traditionally marked the shift to an impeachment
    inquiry by adopting a resolution that authorizes a committee to investigate
    through court-like procedures differing significantly from those used in
    routine oversight. See, e.g., Jefferson’s Manual § 606, at 324 (recognizing
    10
    House Committees’ Authority to Investigate for Impeachment
    that, in modern practice, “the sentiment of committees has been in favor
    of permitting the accused to explain, present witnesses, cross-examine,
    and be represented by counsel” (citations omitted)); see also Cong. Re-
    search Serv., R45983, Congressional Access to Information in an Im-
    peachment Investigation 15 (Oct. 25, 2019) (“[D]uring both the Nixon
    and Clinton impeachment investigations, the House Judiciary Committee
    adopted resolutions affording the President and his counsel the right to
    respond to evidence gathered by the committee, raise objections to testi-
    mony, and cross-examine witnesses[.]”).12 A House resolution authorizing
    the opening of an impeachment inquiry plays a highly significant role in
    directing the scope and nature of the constitutional inquest that follows.
    Such a resolution does not just reflect traditional practice. It is a consti-
    tutionally required step before a committee may exercise compulsory
    process in aid of the House’s “sole Power of Impeachment.” U.S. Const.
    art. I, § 2, cl. 5. In this Part, we explain the basis for this conclusion. First,
    we address the constitutional distinction between the House’s power to
    investigate for legislative purposes and for impeachment purposes. We
    next explain why an impeachment inquiry must be authorized by the
    House itself. Finally, we review the historical record, which confirms,
    across dozens of examples, that the House must specifically authorize
    12 The House Judiciary Committee permitted President Nixon’s counsel to submit and
    respond to evidence, to request to call witnesses, to attend hearings and examinations, to
    object to the examination of witnesses and the admissibility of testimony, and to question
    witnesses. See H.R. Rep. No. 93-1305, at 8–9 (1974); 3 Deschler’s Precedents ch. 14,
    § 6.5, at 2045–47. Later, President Clinton and his counsel were similarly “invited to
    attend all executive session and open committee hearings,” at which they were permitted
    to “cross examine witnesses,” “make objections regarding the pertinency of evidence,”
    “suggest that the Committee receive additional evidence,” and “respond to the evidence
    adduced by the Committee.” H.R. Rep. No. 105-795, at 25–26; see also 18 Deschler’s
    Precedents app. at 549 (2013) (noting that, during the Clinton impeachment investigation,
    the House made a “deliberate attempt to mirror [the] documented precedents and proceed-
    ings” of the Nixon investigation). In a departure from the Nixon and Clinton precedents,
    the House committees did not provide President Trump with any right to attend, partici-
    pate in, or cross-examine witnesses in connection with the impeachment-related deposi-
    tions conducted by the three committees before October 31. Resolution 660 similarly did
    not provide any such rights with respect to any of the public hearings conducted by
    HPSCI, limiting the President’s opportunity to participate to the Judiciary Committee,
    which did not itself participate in developing the investigative record upon which the
    articles of impeachment were premised. See H.R. Res. 660, 116th Cong. § 4(a); 165 Cong.
    Rec. E1357 (daily ed. Oct. 29, 2019) (“Impeachment Inquiry Procedures in the Commit-
    tee on the Judiciary”).
    11
    Opinions of the Office of Legal Counsel in Volume 44
    committees to conduct impeachment investigations and to issue compul-
    sory process.
    A.
    The Constitution vests several different powers in the House of Repre-
    sentatives. As one half of Congress, the House shares with the Senate
    the “legislative Powers” granted in the Constitution (U.S. Const. art. I,
    § 1), which include the ability to pass bills (
    id. art. I,
    § 7, cl. 2) and to
    override presidential vetoes (
    id. art. I,
    § 7, cl. 3) in the process of enacting
    laws pursuant to Congress’s enumerated legislative powers (e.g., 
    id. art. I,
    § 8), including the power to appropriate federal funds (
    id. art. I,
    § 9, cl. 7).
    But the House has other, non-legislative powers. It is, for instance, “the
    Judge of the Elections, Returns and Qualifications of its own Members.”
    
    Id. art. I,
    § 5, cl. 1. And it has “the sole Power of Impeachment.” 
    Id. art. I,
    § 2, cl. 5.
    The House and Senate do not act in a legislative role in connection with
    impeachment. The Constitution vests the House with the authority to
    accuse civil officers of “Treason, Bribery, or other high Crimes and
    Misdemeanors” that warrant removal and disqualification from office.
    U.S. Const. art. I, § 2, cl. 5; 
    id. art. I,
    § 3, cl. 7; 
    id. art. II,
    § 4. As Alexan-
    der Hamilton explained, the members of the House act as “the inquisitors
    for the nation.” The Federalist No. 65, at 440 (Jacob E. Cooke ed., 1961).
    And Senators, in turn, act “in their judicial character as a court for the
    trial of impeachments.” 
    Id. at 439;
    see also The Federalist No. 66, at 445–
    46 (defending the “partial intermixture” in the impeachment context of
    usually separated powers as “not only proper, but necessary to the mutual
    defense of the several members of the government, against each other”;
    noting that dividing “the right of accusing” from “the right of judging”
    between “the two branches of the legislature . . . avoids the inconvenience
    of making the same persons both accusers and judges”). The House’s
    impeachment authority differs fundamentally in character from its legisla-
    tive power.
    With respect to both its legislative and its impeachment powers, the
    House has corresponding powers of investigation, which enable it to
    collect the information necessary for the exercise of those powers. The
    Supreme Court has explained that “[t]he power of inquiry—with process
    to enforce it—is an essential and appropriate auxiliary to the legislative
    function.” 
    McGrain, 273 U.S. at 174
    . Thus, in the legislative context,
    12
    House Committees’ Authority to Investigate for Impeachment
    the House’s investigative power “encompasses inquiries concerning the
    administration of existing laws as well as proposed or possibly needed
    statutes.” Watkins v. United States, 
    354 U.S. 178
    , 187 (1957); see also
    Scope of Congressional Oversight and Investigative Power with Respect
    to the Executive Branch, 
    9 Op. O.L.C. 60
    , 60 (1985) (“Congress may
    conduct investigations in order to obtain facts pertinent to possible legis-
    lation and in order to evaluate the effectiveness of current laws.”). The
    Court has further recognized that the House also has implied powers to
    investigate in support of its other powers, including its power of im-
    peachment. See, e.g., Kilbourn v. Thompson, 
    103 U.S. 168
    , 190 (1880);
    see also In re Request for Access to Grand Jury Materials, 
    833 F.2d 1438
    ,
    1445 (11th Cir. 1987) (the House “holds investigative powers that are
    ancillary to its impeachment power”); Mazars 
    USA, 940 F.3d at 749
    (Rao,
    J., dissenting) (“The House . . . has a separate power to investigate pursu-
    ant to impeachment[.]”).
    Because the House has different investigative powers, establishing
    which authority has been delegated has often been necessary in the course
    of determining the scope of a committee’s authority to compel witnesses
    and testimony. In addressing the scope of the House’s investigative pow-
    ers, all three branches of the federal government have recognized the
    constitutional distinction between a legislative investigation and an im-
    peachment inquiry.
    1.
    We begin with the federal courts. In Kilbourn, the Supreme Court held
    that a House committee could not investigate a bankrupt company indebt-
    ed to the United States because its request exceeded the scope of the
    legislative power. According to the Court, the committee had employed
    investigative power to promote the United States’ interests as a creditor,
    rather than for any valid legislative purpose. 
    See 103 U.S. at 192
    –95. At
    the same time, the Court conceded that “the whole aspect of the case
    would have been changed” if “any purpose had been avowed to impeach
    the [S]ecretary” of the Navy for mishandling the debts of the United
    States. 
    Id. at 193.
    But, after reviewing the resolution authorizing the
    actions of the committee, the Court confirmed that the House had not
    authorized any impeachment inquiry. 
    Id. In a
    similar vein, the D.C. Circuit distinguished the needs of the House
    Judiciary Committee, which was conducting an impeachment inquiry into
    13
    Opinions of the Office of Legal Counsel in Volume 44
    the actions of President Nixon, from those of the Senate Select Committee
    on Presidential Campaign Activities, whose investigation was premised
    upon legislative oversight. See Senate Select 
    Comm., 498 F.2d at 732
    . The
    court recognized that the impeachment investigation was rooted in “an
    express constitutional source” and that the House committee’s investiga-
    tive needs differed in kind from the Senate committee’s oversight needs.
    
    Id. In finding
    that the Senate committee had not demonstrated that Presi-
    dent Nixon’s audiotapes were “critical to the performance of its legisla-
    tive functions,” the court recognized “a clear difference between Con-
    gress’s legislative tasks and the responsibility of a grand jury, or any
    institution engaged in like functions,” such as the House Judiciary Com-
    mittee, which had “begun an inquiry into presidential impeachment.” 
    Id. (emphases added).
       More recently, the D.C. Circuit acknowledged this same distinction in
    Mazars USA. As the majority opinion explained, “the Constitution has left
    to Congress the judgment whether to commence the impeachment pro-
    cess” and to decide whether the conduct in question is “better addressed
    through oversight and legislation than 
    impeachment.” 940 F.3d at 739
    .
    Judge Rao’s dissent also recognized the distinction between a legislative
    oversight investigation and an impeachment inquiry. See 
    id. at 757
    (“The
    Framers established a mechanism for Congress to hold even the highest
    officials accountable, but also required the House to take responsibility
    for invoking this power.”). Judge Rao disagreed with the majority insofar
    as she understood Congress’s impeachment power to be the sole means
    for investigating past misconduct by impeachable officers. But both the
    majority and the dissent agreed with the fundamental proposition that the
    Constitution distinguishes between investigations pursuant to the House’s
    impeachment authority and those that serve its legislative authority (in-
    cluding oversight).
    2.
    The Executive Branch similarly has long distinguished between inves-
    tigations for legislative and for impeachment purposes. In 1796, the
    House “[r]esolved” that President Washington “be requested to lay before
    th[e] House a copy of the instructions” given to John Jay in preparation
    for his negotiation of a peace settlement with Great Britain. 5 Annals of
    Cong. 759–62 (1796). Washington refused to comply because the Consti-
    tution contemplates that only the Senate, not the House, must consent to
    14
    House Committees’ Authority to Investigate for Impeachment
    a treaty. See 
    id. at 760–61.
    “It d[id] not occur” to Washington “that the
    inspection of the papers asked for, c[ould] be relative to any purpose
    under the cognizance of the House of Representatives, except that of an
    impeachment.” 
    Id. at 760
    (emphasis added). Because the House’s “resolu-
    tion ha[d] not expressed” any purpose of pursuing impeachment, Wash-
    ington concluded that “a just regard to the constitution . . . forb[ade] a
    compliance with [the House’s] request” for documents. 
    Id. at 760
    , 762.
    In 1832, President Jackson drew the same line. A select committee of
    the House had requested that the Secretary of War “furnish[]” it “with
    a copy” of an unratified 1830 treaty with the Chickasaw Tribe and “the
    journal of the commissioners” who negotiated it. H.R. Rep. No. 22-488,
    at 1 (1832). The Secretary conferred with Jackson, who refused to comply
    with the committee’s request on the same ground cited by President
    Washington: he “d[id] not perceive that a copy of any part of the incom-
    plete and unratified treaty of 1830, c[ould] be ‘relative to any purpose
    under the cognizance of the House of Representatives, except that of an
    impeachment, which the resolution has not expressed.’” 
    Id. at 14
    (reprint-
    ing Letter for Charles A. Wickliffe, Chairman, Committee on Public
    Lands, U.S. House of Representatives, from Lewis Cass, Secretary of War
    (Mar. 2, 1832)).
    In 1846, another House select committee requested that President Polk
    account for diplomatic expenditures made in previous administrations by
    Secretary of State Daniel Webster. Polk refused to disclose information
    but “cheerfully admitted” that the House may have been entitled to such
    information if it had “institute[d] an [impeachment] inquiry into the
    matter.” Cong. Globe, 29th Cong., 1st Sess. 698 (1846). 13 Notably, he
    13 In denying the congressional request before him, President Polk suggested, in the
    equivalent of dictum, that, during an impeachment inquiry, “all the archives and papers of
    the Executive departments, public or private, would be subject to the inspection and
    control of a committee of their body.” Cong. Globe, 29th Cong., 1st Sess. 698 (1846).
    That statement, however, dramatically understates the degree to which executive privilege
    remains available during an impeachment investigation to protect confidentiality interests
    necessary to preserve the essential functions of the Executive Branch. See Exclusion of
    Agency Counsel from Congressional Depositions in the Impeachment Context, 43 Op.
    O.L.C. __, at *3 & n.1 (Nov. 1, 2019). In a prior opinion, this Office viewed Polk as
    acknowledging the continued availability of executive privilege, because we read Polk’s
    preceding sentence as “indicat[ing]” that, even in the impeachment context, “the Execu-
    tive branch ‘would adopt all wise precautions to prevent the exposure of all such matters
    the publication of which might injuriously affect the public interest, except so far as
    15
    Opinions of the Office of Legal Counsel in Volume 44
    took this position even though some members of Congress had suggested
    that evidence about the expenditures could support an impeachment of
    Webster. 14 In these and other instances, the Executive Branch has consist-
    ently drawn a distinction between the power of legislative oversight and
    the power of impeachment. See Mazars 
    USA, 940 F.3d at 761
    –64 (Rao, J.,
    dissenting) (discussing examples from the Buchanan, Grant, Cleveland,
    Theodore Roosevelt, and Coolidge Administrations).
    3.
    House members, too, have consistently recognized the difference be-
    tween a legislative oversight investigation and an impeachment investiga-
    tion. See Alissa M. Dolan et al., Cong. Research Serv., RL30240, Con-
    gressional Oversight Manual 25 (Dec. 19, 2014) (“A committee’s inquiry
    must have a legislative purpose or be conducted pursuant to some other
    constitutional power of Congress, such as the authority . . . to . . . conduct
    impeachment proceedings.” (emphases added)); Cong. Research Serv.,
    Congressional Access to Information in an Impeachment Investigation
    at 1 (distinguishing between “legislative investigation[s]” and “[m]uch
    more rare[]” “impeachment investigation[s]”).
    For instance, in 1793, when debating the House’s jurisdiction to inves-
    tigate Secretary of the Treasury Alexander Hamilton, some members
    argued that the House could not adopt a resolution of investigation into
    Hamilton’s conduct without adopting the “solemnities and guards” of an
    impeachment inquiry. See, e.g., 3 Annals of Cong. 903 (1793) (statement
    of Rep. Smith); 
    id. at 947–48
    (statement of Rep. Boudinot) (distinguish-
    ing between the House’s “Legislative capacity” and its role as “the grand
    inquest of the Nation”); see also Mazars 
    USA, 940 F.3d at 758
    (Rao, J.,
    dissenting) (discussing the episode). In 1796, when the House debated
    this might be necessary to accomplish the great ends of public justice.’” Memorandum
    for Elliot Richardson, Attorney General, from Robert G. Dixon, Jr., Assistant Attorney
    General, Office of Legal Counsel, Re: Presidential Immunity from Coercive Congression-
    al Demands for Information at 22–23 (July 24, 1973) (quoting Polk’s letter).
    14 See, e.g., Cong. Globe, 29th Cong., 1st Sess. 636 (1846) (statement of Rep. Inger-
    soll) (“Whether . . . [Webster’s] offences will be deemed impeachable misdemeanors in
    office, conviction for which might remove him from the Senate, and disqualify him to
    hold any office of honor, trust, or profit, under the United States, will remain to be
    considered.”); Todd Garvey, The Webster and Ingersoll Investigations, in Morton Rosen-
    berg, The Constitution Project, When Congress Comes Calling 289 (2017).
    16
    House Committees’ Authority to Investigate for Impeachment
    whether to request the President’s instructions for negotiating the Jay
    Treaty, Representative Murray concluded that the House could not med-
    dle in treatymaking, but acknowledged that “the subject would be pre-
    sented under an aspect very different” if the resolution’s supporters had
    “stated the object for which they called for the papers to be an impeach-
    ment.” 5 Annals of Cong. 429–30 (1796).
    Similarly, in 1846, a House select committee agreed with President
    Polk’s decision not to turn over requested information regarding State
    Department expenditures where the House did not act “with a view to an
    impeachment.” H.R. Rep. No. 29-684, at 4 (1846) (noting that four of the
    committee’s five members “entirely concur with the President of the
    United States” in deciding not to “communicate or make [the requested
    documents] public, except with a view to an impeachment” and that “[n]o
    dissent from the views of that message was expressed by the House”); see
    also Mazars 
    USA, 940 F.3d at 761
    (Rao, J., dissenting). To take another
    example, in 1879, the House Judiciary Committee distinguished “[i]n-
    vestigations looking to the impeachment of public officers” from “an
    ordinary investigation for legislative purposes.” H.R. Rep. No. 45-141,
    at 2 (1879).
    Most significantly, during the impeachments of Presidents Nixon and
    Clinton, the House Judiciary Committee determined that the House must
    provide express authorization before any committee may exercise com-
    pulsory powers in an impeachment investigation. See infra Part II.C.1.
    Thus, members of the House, like the other branches of government, have
    squarely recognized the distinction between congressional investigations
    for impeachment purposes and those for legislative purposes.
    B.
    Although the House of Representatives has “the sole Power of Im-
    peachment,” U.S. Const. art. I, § 2, cl. 5 (emphasis added), the associated
    power to conduct an investigation for impeachment purposes may, like the
    House’s other investigative powers, be delegated. The full House may
    make such a delegation by adopting a resolution in exercise of its authori-
    ty to determine the rules for its proceedings, see 
    id. art. I,
    § 5, cl. 2, and
    each House has broad discretion in determining the conduct of its own
    proceedings. See, e.g., NLRB v. Noel Canning, 
    573 U.S. 513
    , 551–52
    (2014); United States v. Ballin, 
    144 U.S. 1
    , 5 (1892); see also 1 Desch-
    ler’s Precedents ch. 5, § 4, at 305−06. But the House must actually exer-
    17
    Opinions of the Office of Legal Counsel in Volume 44
    cise its discretion by making that judgment in the first instance, and its
    resolution sets the terms of a committee’s authority. See United States v.
    Rumely, 
    345 U.S. 41
    , 44 (1953). No committee may exercise the House’s
    investigative powers in the absence of such a delegation.
    As the Supreme Court has explained in the context of legislative over-
    sight, “[t]he theory of a committee inquiry is that the committee members
    are serving as the representatives of the parent assembly in collecting
    information for a legislative purpose” and, in such circumstances, com-
    mittees “are endowed with the full power of the Congress to compel
    testimony.” 
    Watkins, 354 U.S. at 200
    –01. The same is true for impeach-
    ment investigations. 15 Thus, Hamilton recognized, the impeachment
    power involves a trust of such “delicacy and magnitude” that it “deeply
    concerns the political reputation and existence of every man engaged in
    the administration of public affairs.” The Federalist No. 65, at 440. The
    Founders foresaw that an impeachment effort would “[i]n many cases . . .
    connect itself with the pre-existing factions” and “inlist all their animosi-
    ties, partialities, influence and interest on one side, or on the other.” 
    Id. at 439.
    As a result, they placed the solemn authority to initiate an impeach-
    ment in “the representatives of the nation themselves.” 
    Id. at 440.
    In order
    to entrust one of its committees to investigate for purposes of impeach-
    ment, the full House must “spell out that group’s jurisdiction and pur-
    pose.” 
    Watkins, 354 U.S. at 201
    . Otherwise, a House committee con-
    15 When the House first considered impeachment in 1796, Attorney General Charles
    Lee advised that, “before an impeachment is sent to the Senate, witnesses must be exam-
    ined, in solemn form, respecting the charges, before a committee of the House of Repre-
    sentatives, to be appointed for that purpose.” Letter for the House of Representatives from
    Charles Lee, Attorney General, Re: Inquiry into the Official Conduct of a Judge of the
    Supreme Court of the Northwestern Territory (May 9, 1796), reprinted in 1 Am. State
    Papers: Misc. 151 (Walter Lowrie & Walter S. Franklin eds., 1834). Because the charges
    of misconduct concerned the actions of George Turner, a territorial judge, and the wit-
    nesses were located in far-away St. Clair County (modern-day Illinois), Lee suggested
    that the “most solemn” mode of prosecution, an impeachment trial before the Senate,
    would be “very inconvenient, if not entirely impracticable.” 
    Id. Lee informed
    the House
    that President Washington had directed the territorial governor to arrange for a criminal
    prosecution before the territorial court. See 
    id. The House
    committee considering the
    petition about Turner agreed with Lee’s suggestion and recommended that the House take
    no further action. See Inquiry into the Official Conduct of a Judge of the Supreme Court
    of the Northwestern Territory (Feb. 27, 1797), reprinted in 1 Am. State Papers: Misc. at
    157.
    18
    House Committees’ Authority to Investigate for Impeachment
    trolled by such a faction could launch open-ended and untethered investi-
    gations without the sanction of a majority of the House.
    Because a committee may exercise the House’s investigative powers
    only when authorized, the committee’s actions must be within the scope
    of a resolution delegating authority from the House to the committee. As
    the D.C. Circuit recently explained, “it matters not whether the Constitu-
    tion would give Congress authority to issue a subpoena if Congress has
    given the issuing committee no such authority.” Mazars 
    USA, 940 F.3d at 722
    ; see Dolan, Congressional Oversight Manual at 24 (“Committees of
    Congress only have the power to inquire into matters within the scope of
    the authority delegated to them by their parent body.”). In evaluating a
    committee’s authority, the House’s resolution “is the controlling charter
    of the committee’s powers,” and, therefore, the committee’s “right to
    exact testimony and to call for the production of documents must be found
    in this language.” 
    Rumely, 345 U.S. at 44
    ; see also 
    Watkins, 354 U.S. at 201
    (“Those instructions are embodied in the authorizing resolution. That
    document is the committee’s charter.”); 
    id. at 206
    (“Plainly [the House’s]
    committees are restricted to the missions delegated to them . . . . No
    witness can be compelled to make disclosures on matters outside that
    area.”); Exxon Corp. v. FTC, 
    589 F.2d 582
    , 592 (D.C. Cir. 1978) (“To
    issue a valid subpoena, . . . a committee or subcommittee must conform
    strictly to the resolution establishing its investigatory powers[.]”); United
    States v. Lamont, 
    18 F.R.D. 27
    , 32 (S.D.N.Y. 1955) (Weinfeld, J.) (“No
    committee of either the House or Senate, and no Senator and no Repre-
    sentative, is free on its or his own to conduct investigations unless author-
    ized. Thus it must appear that Congress empowered the Committee to act,
    and further that at the time the witness allegedly defied its authority the
    Committee was acting within the power granted to it.”). While a commit-
    tee may study some matters without exercising the investigative powers of
    the House, a committee’s authority to compel the production of docu-
    ments and testimony depends entirely upon the jurisdiction provided by
    the terms of the House’s delegation.
    In Watkins, the Supreme Court relied upon those principles to set aside
    a conviction for contempt of Congress because of the authorizing resolu-
    tion’s vagueness. The uncertain scope of the House’s delegation imper-
    missibly created “a wide gulf between the responsibility for the use of
    investigative power and the actual exercise of that 
    power.” 354 U.S. at 205
    . If the House wished to authorize the exercise of its investigative
    power, then it needed to take responsibility for the use of that power,
    19
    Opinions of the Office of Legal Counsel in Volume 44
    because a congressional subpoena, issued with the threat of a criminal
    contempt citation, necessarily placed “constitutional liberties” in “dan-
    ger.” 
    Id. The concerns
    expressed by the Court in Watkins apply with equal, if
    not greater, force when considering the authority of a House committee to
    compel the production of documents in connection with investigating
    impeachment. As John Labovitz, a House impeachment attorney during
    the Nixon investigation, explained: “[I]mpeachment investigations, be-
    cause they involve extraordinary power and (at least where the president
    is being investigated) may have extraordinary consequences, are not to be
    undertaken in the same manner as run-of-the-mill legislative investiga-
    tions. The initiation of a presidential impeachment inquiry should itself
    require a deliberate decision by the House.” John R. Labovitz, Presiden-
    tial Impeachment 184 (1978). Because a committee possesses only the
    authorities that have been delegated to it, a committee may not use com-
    pulsory process to investigate impeachment without the formal authoriza-
    tion of the House.
    C.
    Historical practice confirms that the House must authorize an im-
    peachment inquiry. See, e.g., Zivotofsky v. Kerry, 
    135 S. Ct. 2076
    , 2091
    (2015) (recognizing that “[i]n separation-of-powers cases,” the Court has
    placed “significant weight” on “accepted understandings and practice”);
    Noel 
    Canning, 573 U.S. at 514
    (same). The House has expressly author-
    ized every impeachment investigation of a President, including by identi-
    fying the investigative committee and authorizing the use of compulsory
    process. The same thing has been true for nearly all impeachment investi-
    gations of other executive officials and judges. While committees have
    sometimes studied a proposed impeachment resolution or reviewed avail-
    able information without conducting a formal investigation, in nearly
    every case in which the committee resorted to compulsory process, the
    House expressly authorized the impeachment investigation. That practice
    was foreseen as early as 1796. When Washington asked his Cabinet for
    opinions about how to respond to the House’s request for the papers
    associated with the Jay Treaty, the Secretary of the Treasury, Oliver
    Wolcott Jr., explained that “the House of Representatives has no right to
    demand papers” outside its legislative function “[e]xcept when an Im-
    peachment is proposed & a formal enquiry instituted.” Letter for George
    20
    House Committees’ Authority to Investigate for Impeachment
    Washington from Oliver Wolcott Jr. (Mar. 26, 1796), reprinted in 19 The
    Papers of George Washington: Presidential Series 611–12 (David R.
    Hoth ed., 2016) (emphasis added).
    From the very first impeachment, the House has recognized that a
    committee would require a delegation to conduct an impeachment inquiry.
    In 1797, when House members considered whether a letter contained
    evidence of criminal misconduct by Senator William Blount, they sought
    to confirm Blount’s handwriting but concluded that the Committee of the
    Whole did not have the power of taking evidence. See 7 Annals of Cong.
    456–58 (1797); 3 Asher C. Hinds, Hinds’ Precedents of the House of
    Representatives of the United States § 2294, at 644–45 (1907). Thus, the
    committee “rose,” and the House itself took testimony. 3 Hinds’ Prece-
    dents § 2294, at 646. Two days later, the House appointed a select com-
    mittee to “prepare and report articles of impeachment” and vested in that
    committee the “power to send for persons, papers, and records.” 7 Annals
    of Cong. at 463–64, 466; 3 Hinds’ Precedents § 2297, at 648. 16 As we
    discuss in this section, we have identified dozens of other instances where
    the House, in addition to referring proposed articles of impeachment,
    authorized formal impeachment investigations.
    Against this weighty historical record, which involves nearly 100 au-
    thorized impeachment investigations, the outliers are few and far be-
    tween. 17 In 1879, it appears that a House committee, which was expressly
    authorized to conduct an oversight investigation into the administration of
    the U.S. consulate in Shanghai, ultimately investigated and recommended
    that the former consul-general and former vice consul-general be im-
    peached. In addition, between 1986 and 1989, the Judiciary Committee
    considered the impeachment of three federal judges who had been crimi-
    nally prosecuted (two of whom had been convicted). The Judiciary Com-
    mittee pursued impeachment before there had been any House vote, and
    issued subpoenas in two of those inquiries. Since then, however, the
    Judiciary Committee reaffirmed during the impeachment of President
    16 After the House impeached Senator Blount, the Senate voted to dismiss the charges
    on the ground that a Senator is not a civil officer subject to impeachment. See 3 Hinds’
    Precedents § 2318, at 678–80.
    17 A 2007 overview concluded that “[t]here have been approximately 94 identifiable
    impeachment-related inquiries conducted by Congress[.]” H.R. Doc. No. 109-153, at 115
    (2007). Since 2007, two more judges have been impeached following authorized investi-
    gations.
    21
    Opinions of the Office of Legal Counsel in Volume 44
    Clinton that, in order to conduct an impeachment investigation, it needed
    an express delegation of investigative authority from the House. And in
    all subsequent cases the House has hewed to the well-established practice
    of authorizing each impeachment investigation.
    The U.S. District Court for the District of Columbia recently reviewed
    a handful of historical examples and concluded that House committees
    may conduct impeachment investigations without a vote of the full House.
    See In re Application of the Comm. on the Judiciary, 
    2019 WL 5485221
    ,
    at *26–28. Yet, as the discussion below confirms, the district court mis-
    read the lessons of history. 18 The district court treated the House Judiciary
    Committee’s preliminary inquiries in the Clinton and Nixon impeach-
    ments as investigations, without recognizing that, in both cases, the com-
    mittee determined that a full House vote was necessary before it could
    issue subpoenas. The district court also treated the 1980s judicial inquiries
    as if they represented a rule of practice, rather than a marked deviation
    from the dozens of occasions where the House recognized the need to
    adopt a formal resolution to delegate its investigative authority. As our
    survey below confirms, the historical practice with respect to Presidents,
    other executive officers, and judges is consistent with the structure of our
    Constitution, which requires the House, as the “sole” holder of impeach-
    ment power, to authorize any impeachment investigation that a committee
    may conduct on its behalf.
    18 The district court’s erroneous conclusions rested upon the arguments offered by the
    House Judiciary Committee, which relied principally upon the judicial outliers from the
    1980s, a misunderstanding of the Nixon impeachment inquiry, and a misreading of the
    committee’s subpoena power under the House Rules. See Application at 33−34, In re
    Application of the Comm. on the Judiciary (D.D.C. July 26, 2019); Reply of the Commit-
    tee on the Judiciary, U.S. House of Representatives, in Support of Its Application for an
    Order Authorizing the Release of Certain Grand Jury Materials, at 16 n.19, In re Applica-
    tion of the Comm. on the Judiciary (D.D.C. Sept. 30, 2019). HPSCI and the Judiciary
    Committee later reiterated these arguments in their reports, each contending that execu-
    tive branch officials had “obstructed” the House’s impeachment inquiry by declining to
    comply with the pre-October 31 impeachment-related subpoenas. H.R. Rep. No. 116-335,
    at 168–72, 175–77 (2019); H.R. Rep. No. 116-346, at 10, 13–16 (2019). But those reports
    asserted that the pre-October 31 subpoenas were authorized because the committees
    misunderstood the historical practice concerning the House’s impeachment inquiries (as
    we discuss in Part II.C) and they misread the committees’ subpoena authority under the
    House Rules (as we discuss in Part III.A).
    22
    House Committees’ Authority to Investigate for Impeachment
    1.
    While many Presidents have been the subject of less-formal demands
    for impeachment, at least eleven have faced resolutions introduced in the
    House for the purpose of initiating impeachment proceedings. 19 In some
    cases, the House formally voted to reject opening a presidential impeach-
    ment investigation. In 1843, the House rejected a resolution calling for an
    investigation into the impeachment of President Tyler. See Cong. Globe,
    27th Cong., 3d Sess. 144−46 (1843). In 1932, the House voted by a wide
    margin to table a similar resolution introduced against President Hoover.
    See 76 Cong. Rec. 399–402 (1932). In many other cases, the House simp-
    ly referred impeachment resolutions to the Judiciary Committee, which
    took no further action before the end of the Congress. But, in three in-
    stances before President Trump, the House moved forward with investi-
    gating the impeachment of a President. 20 Each of those presidential im-
    peachments advanced to the investigative stage only after the House
    19  See, e.g., Cong. Globe, 27th Cong., 3d Sess. 144, 146 (1843) (John Tyler); Cong.
    Globe, 39th Cong., 2d Sess. 320 (1867) (Andrew Johnson); 28 Cong. Rec. 5627, 5650
    (1896) (Grover Cleveland); 76 Cong. Rec. 399–402 (1932) (Herbert Hoover); H.R. Res.
    607, 82d Cong. (1952) (Harry Truman); H.R. Res. 625, 93d Cong. (1973) (Richard
    Nixon); H.R. Res. 370, 98th Cong. (1983) (Ronald Reagan); H.R. Res. 34, 102d Cong.
    (1991) (George H.W. Bush); H.R. Res. 525, 105th Cong. (1998) (Bill Clinton); H.R. Res.
    1258, 110th Cong. (2008) (George W. Bush); H.R. Res. 13, 106th Cong. (2019) (Donald
    Trump).
    20 In 1860, the House authorized an investigation into the actions of President Buchan-
    an, but that investigation was not styled as an impeachment investigation. See Cong.
    Globe, 36th Cong., 1st Sess. 997–98 (1860) (resolution establishing a committee of five
    members to “investigat[e] whether the President of the United States, or any other officer
    of the government, ha[d], by money, patronage, or other improper means, sought to
    influence the action of Congress” or “by combination or otherwise, . . . attempted to
    prevent or defeat, the execution of any law”). It appears to have been understood by the
    committee as an oversight investigation. See H.R. Rep. No. 36-648, at 1–28 (1860).
    Buchanan in fact objected to the House’s use of its legislative jurisdiction to circumvent
    the protections traditionally provided in connection with impeachment. See Message
    for the U.S. House of Representatives from James Buchanan (June 22, 1860), reprinted in
    5 A Compilation of the Messages and Papers of the Presidents 625 (James D. Richardson
    ed., 1897) (objecting that if the House suspects presidential misconduct, it should “trans-
    fer the question from [its] legislative to [its] accusatory jurisdiction, and take care that in
    all the preliminary judicial proceedings preparatory to the vote of articles of impeachment
    the accused should enjoy the benefit of cross-examining the witnesses and all the other
    safeguards with which the Constitution surrounds every American citizen”); see also
    Mazars 
    USA, 940 F.3d at 762
    (Rao, J., dissenting) (discussing the episode).
    23
    Opinions of the Office of Legal Counsel in Volume 44
    adopted a resolution expressly authorizing a committee to conduct the
    investigation. In no case did the committee use compulsory process until
    the House had expressly authorized the impeachment investigation.
    The impeachment investigation of President Andrew Johnson. On
    January 7, 1867, the House adopted a resolution authorizing the “Commit-
    tee on the Judiciary” to “inquire into the official conduct of Andrew
    Johnson . . . and to report to this House whether, in their opinion,” the
    President “has been guilty of any act, or has conspired with others to do
    acts, which, in contemplation of the Constitution, are high crimes or
    misdemeanors.” Cong. Globe, 39th Cong., 2d Sess. 320–21 (1867); see
    also 3 Hinds’ Precedents § 2400, at 824. The resolution conferred upon
    the committee the “power to send for persons and papers and to adminis-
    ter the customary oath to witnesses.” Cong. Globe, 39th Cong., 2d Sess.
    320 (1867). The House referred a second resolution to the Judiciary
    Committee on February 4, 1867. 
    Id. at 991;
    3 Hinds’ Precedents § 2400,
    at 824. 21 Shortly before that Congress expired, the committee reported
    that it had seen “sufficient testimony . . . to justify and demand a further
    prosecution of the investigation.” H.R. Rep. No. 39-31, at 2 (1867). On
    March 7, 1867, the House in the new Congress adopted a resolution that
    authorized the committee “to continue the investigation authorized” in the
    January 7 resolution and to “send for persons and papers” and administer
    oaths. Cong. Globe, 40th Cong., 1st Sess. 18, 25 (1867); 3 Hinds’ Prece-
    dents § 2401, at 825–26. The committee recommended articles of im-
    peachment, but the House rejected those articles on December 7, 1867.
    See Cong. Globe, 40th Cong., 2d Sess. 67–68 (1867). In early 1868,
    however, the House adopted resolutions authorizing another investigation,
    with compulsory powers, by the Committee on Reconstruction and trans-
    ferred to that committee the evidence from the Judiciary Committee’s
    21 The district court’s recent decision in In re Application of the Committee on the Ju-
    diciary misreads Hinds’ Precedents to suggest that the House Judiciary Committee (which
    the court called “HJC”) began investigating President Johnson’s impeachment without
    any authorizing resolution. According to the district court, “a resolution ‘authoriz[ing]’
    HJC ‘to inquire into the official conduct of Andrew Johnson’ was passed after HJC ‘was
    already considering the subject.’” 
    2019 WL 5485221
    , at *27 (quoting 3 Hinds’ Prece-
    dents § 2400, at 824). In fact, the committee was “already considering the subject” at the
    time of the February 4 resolution described in the quoted sentence because, as explained
    in the text above, the House had previously adopted a separate resolution authorizing
    an impeachment investigation. See Cong. Globe, 39th Cong., 2d Sess. 320–21 (1867);
    3 Hinds’ Precedents § 2400, at 824.
    24
    House Committees’ Authority to Investigate for Impeachment
    earlier investigation. See Cong. Globe, 40th Cong., 2d Sess. 784–85, 1087
    (1868); 3 Hinds’ Precedents § 2408, at 845.
    On February 21, 1868, the impeachment effort received new impetus
    when Johnson removed the Secretary of War without the Senate’s ap-
    proval, contrary to the terms of the Tenure of Office Act, which Johnson
    (correctly) held to be an unconstitutional limit on his authority. See
    Cong. Globe, 40th Cong., 2d Sess. 1326–27 (1868); 3 Hinds’ Precedents
    § 2408–09, at 845–47; see also Myers v. United States, 
    272 U.S. 52
    , 176
    (1926) (finding that provision of the Tenure of Office Act “was invalid”).
    That day, the Committee on Reconstruction reported an impeachment
    resolution to the House, which was debated on February 22 and passed on
    February 24. Cong. Globe, 40th Cong., 2d Sess. 1400 (1868); 3 Hinds’
    Precedents §§ 2409–12, at 846–51.
    The impeachment investigation of President Nixon. Although many
    resolutions were introduced in support of President Nixon’s impeachment
    earlier in 1973, the House’s formal impeachment inquiry arose in the
    months following the “Saturday Night Massacre,” during which President
    Nixon caused the termination of Special Prosecutor Archibald Cox at the
    cost of the resignations of his Attorney General and Deputy Attorney
    General. See Letter Directing the Acting Attorney General to Discharge
    the Director of the Office of Watergate Special Prosecution Force (Oct.
    20, 1973), Pub. Papers of Pres. Richard Nixon 891 (1973). Immediately
    thereafter, House members introduced resolutions calling either for the
    President’s impeachment or for the opening of an investigation. 22 The
    Speaker of the House referred the resolutions calling for an investigation
    to the Rules Committee and those calling for impeachment to the Judici-
    ary Committee. See Office of Legal Counsel, U.S. Dep’t of Justice, Legal
    Aspects of Impeachment: An Overview at 40 (Feb. 1974) (“Legal Aspects
    of Impeachment ”); 3 Deschler’s Precedents ch. 14, § 5, at 2020.
    Following the referrals, the Judiciary Committee “beg[a]n an inquiry
    into whether President Nixon ha[d] committed any offenses that could
    lead to impeachment,” an exercise that the committee considered “prelim-
    inary.” Richard L. Madden, Democrats Agree on House Inquiry into Nixon’s
    Acts, N.Y. Times, Oct. 23, 1973, at 1. The committee started collecting
    publicly available materials, and Chairman Peter Rodino Jr. stated that he
    22 See, e.g., H.R. Res. 625, 631, 635, and 638, 93d Cong. (1973) (impeachment); H.R.
    Res. 626, 627, 628, 636, and 637, 93d Cong. (1973) (Judiciary Committee or subcommit-
    tee investigation).
    25
    Opinions of the Office of Legal Counsel in Volume 44
    would “set up a separate committee staff to ‘collate’ investigative files
    from Senate and House committees that have examined a variety of
    charges against the Nixon Administration.” James M. Naughton, Rodino
    Vows Fair Impeachment Inquiry, N.Y. Times, Oct. 30, 1973, at 32.
    Although the committee “adopted a resolution permitting Mr. Rodino
    to issue subpoenas without the consent of the full committee,” James M.
    Naughton, House Panel Starts Inquiry on Impeachment Question, N.Y.
    Times, Oct. 31, 1973, at 1, no subpoenas were ever issued under that
    purported authority. Instead, the committee “delayed acting” on the im-
    peachment resolutions. James M. Naughton, House Unit Looks to Im-
    peachment, N.Y. Times, Dec. 2, 1973, at 54. By late December, the com-
    mittee had hired a specialized impeachment staff. A Hard-Working Legal
    Adviser: John Michael Doar, N.Y. Times, Dec. 21, 1973, at 20. The staff
    continued “‘wading through the mass of material already made public,’”
    and the committee’s members began considering “the areas in which the
    inquiry should go.” Bill Kovach, Vote on Subpoena Could Test House
    on Impeachment, N.Y. Times, Jan. 8, 1974, at 14; see also Staff of the
    H. Comm. on the Judiciary, 93d Cong., Rep. on Work of the Impeachment
    Inquiry Staff as of February 5, 1974, at 2–3 (1974) (noting that the staff
    was “first collecting and sifting the evidence available in the public do-
    main,” then “marshaling and digesting the evidence available through
    various governmental investigations”). By January 1974, the committee’s
    actions had consisted of digesting publicly available documents and prior
    impeachment precedents. That was consistent with the committee’s “only
    mandate,” which was to “study more than a dozen impeachment resolu-
    tions submitted” in 1973. James M. Naughton, Impeachment Panel Seeks
    House Mandate for Inquiry, N.Y. Times, Jan. 25, 1974, at 1.
    In January, the committee determined that a formal investigation was
    necessary, and it requested “an official House mandate to conduct the
    inquiry,” relying upon the “precedent in each of the earlier [impeachment]
    inquiries.” 
    Id. at 17.
    On January 7, Chairman Rodino “announced that the
    Committee’s subpoena power does not extend to impeachment and that
    . . . the Committee would seek express authorization to subpoena persons
    and documents with regard to the impeachment inquiry.” Legal Aspects of
    Impeachment at 43; see also Richard L. Lyons, GOP Picks Jenner as
    Counsel, Wash. Post, Jan. 8, 1974, at A1, A6 (“Rodino said the committee
    will ask the House when it reconvenes Jan. 21 to give it power to subpoe-
    na persons and documents for the inquiry. The committee’s subpoena
    power does not now extend to impeachment proceedings, he said.”). As
    26
    House Committees’ Authority to Investigate for Impeachment
    the House Parliamentarian later explained, the Judiciary Committee’s
    general authority to conduct investigations and issue subpoenas “did not
    specifically include impeachments within the jurisdiction of the Commit-
    tee on the Judiciary,” and it was therefore “considered necessary for the
    House to specifically vest the Committee on the Judiciary with the inves-
    tigatory and subpena power to conduct the impeachment investigation.”
    3 Deschler’s Precedents ch. 14, § 15.2, at 2172 (Parliamentarian’s Note).
    On February 6, 1974, the House approved Resolution 803, which “au-
    thorized and directed” the Judiciary Committee “to investigate fully and
    completely whether sufficient grounds exist for the House of Representa-
    tives to exercise its constitutional power to impeach Richard M. Nixon,
    President of the United States of America.” H.R. Res. 803, 93d Cong. § 1.
    The resolution specifically authorized the committee “to require . . . by
    subpena or otherwise . . . the attendance and testimony of any person” and
    “the production of such things” as the committee “deem[ed] necessary” to
    its investigation. 
    Id. § 2(a).
       Speaking on the House floor, Chairman Rodino described the resolu-
    tion as a “necessary step” to confer the House’s investigative powers on
    the Judiciary Committee:
    We have reached the point when it is important that the House ex-
    plicitly confirm our responsibility under the Constitution.
    We are asking the House of Representatives, by this resolution, to
    authorize and direct the Committee on the Judiciary to investigate
    the conduct of the President of the United States . . . .
    As part of that resolution, we are asking the House to give the Ju-
    diciary Committee the power of subpena in its investigations.
    Such a resolution has always been passed by the House. . . . It is a
    necessary step if we are to meet our obligations.
    ....
    . . . The sole power of impeachment carries with it the power to
    conduct a full and complete investigation of whether sufficient
    grounds for impeachment exist or do not exist, and by this resolution
    these investigative powers are conferred to their full extent upon the
    Committee on the Judiciary.
    120 Cong. Rec. 2350–51 (1974) (emphases added). During the debate,
    others recognized that the resolution would delegate the House’s investi-
    gative powers to the Judiciary Committee. See, e.g., 
    id. at 2361
    (statement
    27
    Opinions of the Office of Legal Counsel in Volume 44
    of Rep. Rostenkowski) (“By delegating to the Judiciary Committee the
    powers contained in this resolution, we will be providing that committee
    with the resources it needs to inform the whole House of the facts of this
    case.”); 
    id. at 2362
    (statement of Rep. Boland) (“House Resolution 803 is
    intended to delegate to the Committee on the Judiciary the full extent of
    the powers of this House in an impeachment proceeding[]—both as to the
    persons and types of things that may be subpenaed and the methods for
    doing so.”). Only after the Judiciary Committee had received authoriza-
    tion from the House did it request and subpoena tape recordings and
    documents from President Nixon. See H.R. Rep. No. 93-1305, at 187
    (1974). 23
    The impeachment investigation of President Clinton. On September 9,
    1998, Independent Counsel Kenneth W. Starr, acting under 28 U.S.C.
    § 595(c), advised the House of Representatives that he had uncovered
    substantial and credible information that he believed could constitute
    grounds for the impeachment of President Clinton. 18 Deschler’s Prece-
    dents app. at 548–49 (2013). Two days later, the House adopted a resolu-
    tion that referred the matter, along with Starr’s report and 36 boxes of
    evidence, to the Judiciary Committee. H.R. Res. 525, 105th Cong. (1998).
    The House directed that committee to review the report and “determine
    whether sufficient grounds exist to recommend to the House that an
    impeachment inquiry be commenced.” 
    Id. § 1.
    The Rules Committee’s
    Chairman emphasized that the House would need to adopt a subsequent
    resolution if it decided to authorize an impeachment inquiry: “[T]his
    resolution does not authorize or direct an impeachment inquiry. . . . It
    merely provides the appropriate parameters for the Committee on the
    Judiciary . . . to . . . make a recommendation to the House as to whether
    we should commence an impeachment inquiry.” 144 Cong. Rec. 20021
    (1998) (statement of Rep. Solomon).
    23 A New York Times article the following day characterized House Resolution 803 as
    “formally ratif [ying] the impeachment inquiry begun by the committee [the prior] Octo-
    ber.” James M. Naughton, House, 410-4, Gives Subpoena Power in Nixon Inquiry, N.Y.
    Times, Feb. 7, 1974, at 1. But the resolution did not grant after-the-fact authorization for
    any prior action. To the contrary, the resolution “authorized and directed” a future inves-
    tigation, including by providing subpoena power. In the report recommending adoption of
    the resolution, the committee likewise described its plans in the future tense: “It is the
    intention of the committee that its investigation will be conducted in all respects on a fair,
    impartial and bipartisan basis.” H.R. Rep. No. 93-774, at 3 (1974).
    28
    House Committees’ Authority to Investigate for Impeachment
    On October 7, 1998, the Judiciary Committee did recommend that there
    be an investigation for purposes of impeachment. As explained in the
    accompanying report: “[T]he Committee decided that it must receive
    authorization from the full House before proceeding on any further course
    of action. Because impeachment is delegated solely to the House of Rep-
    resentatives by the Constitution, the full House of Representatives should
    be involved in critical decision making regarding various stages of im-
    peachment.” H.R. Rep. No. 105-795, at 24 (emphasis added). The com-
    mittee also observed that “a resolution authorizing an impeachment in-
    quiry into the conduct of a president is consistent with past practice,”
    citing the resolutions for Presidents Johnson and Nixon and observing that
    “numerous other inquiries were authorized by the House directly, or by
    providing investigative authorities, such as deposition authority, to the
    Committee on the Judiciary.” 
    Id. The next
    day, the House voted to authorize the Judiciary Committee to
    “investigate fully and completely whether sufficient grounds exist for the
    House of Representatives to exercise its constitutional power to impeach
    William Jefferson Clinton, President of the United States of America.”
    H.R. Res. 581, 105th Cong. § 1 (1998). The resolution authorized the
    committee “to require . . . by subpoena or otherwise . . . the attendance
    and testimony of any person” and “the production of . . . things,” and to
    require the furnishing of information “by interrogatory.” 
    Id. § 2(a).
    “On
    November 5, 1998,” as part of its investigation, “the Committee presented
    President Clinton with 81 requests for admission,” which the Committee
    explained that it “would have . . . compelled by subpoena” had President
    Clinton not complied. H.R. Rep. No. 105-830, at 77, 122 (1998). And the
    Committee then “approved the issuance of subpoenas for depositions and
    materials” from several witnesses. 144 Cong. Rec. D1210–11 (daily ed.
    Dec. 17, 1998).
    In discussing the Clinton precedent, the district court in In re Applica-
    tion of the Committee on the Judiciary treated the D.C. Circuit’s approval
    of the disclosure of Starr’s report and associated grand-jury information
    as evidence that the Judiciary Committee may “commence an impeach-
    ment investigation” without a House vote. 
    2019 WL 5485221
    , at *27 &
    n.36. But the D.C. Circuit did not authorize that disclosure because of any
    pending House investigation. It did so because a statutory provision
    required an independent counsel to “advise the House of Representatives
    of any substantial and credible information which such independent
    counsel receives . . . that may constitute grounds for an impeachment.”
    29
    Opinions of the Office of Legal Counsel in Volume 44
    28 U.S.C. § 595(c) (emphasis added). And the D.C. Circuit viewed the
    report as reflecting “information of the type described in 28 U.S.C.
    § 595(c).” In re Madison Guar. Sav. & Loan Ass’n, Div. No. 94-1 (D.C.
    Cir. Spec. Div. July 7, 1998), reprinted in H.R. Doc. No. 105-331, pt. 1,
    at 10 (1998). The order authorizing the transmission of that information to
    the House did not imply that any committee was conducting an impeach-
    ment investigation. To the contrary, after the House received the infor-
    mation, “no person had access to” it until after the House adopted a reso-
    lution referring the matter to the Judiciary Committee. H.R. Rep. No. 105-
    795, at 5. And the House then adopted a second resolution (Resolution
    581) to authorize a formal investigation. In other words, the House voted
    to authorize the Judiciary Committee both to review the Starr evidence
    and to conduct an impeachment investigation. Neither the D.C. Circuit
    nor the Judiciary Committee suggested that any committee could have
    taken such action on its own.
    2.
    The House has historically followed these same procedures in consider-
    ing impeachment resolutions against executive branch officers other than
    the President. In many cases, an initial resolution laying out charges of
    impeachment or authorizing an investigation was referred to a select or
    standing committee. 24 Following such a referral, the designated committee
    24 As with Presidents, many of these resolutions remained with the committees until
    they expired at the end of the Congress. Several merely articulated allegations of im-
    peachment. See, e.g., H.R. Res. 1028, 115th Cong. (2018) (Deputy Attorney General Rod
    Rosenstein); H.R. Res. 417, 114th Cong. (2015) (Administrator of the Environmental
    Protection Agency Regina McCarthy); H.R. Res. 411, 113th Cong. (2013) (Attorney
    General Eric Holder); H.R. Res. 333, 110th Cong. (2007) (Vice President Richard Chen-
    ey); H.R. Res. 629, 108th Cong. (2004) (Secretary of Defense Donald Rumsfeld); H.R.
    Res. 805, 95th Cong. (1977) (United Nations Ambassador Andrew Young); H.R. Res.
    274, 95th Cong. (1977) (Commissioner of the Federal Trade Commission Paul Dixon);
    H.R. Res. 881, 94th Cong. (1975) (U.S. Attorney Jonathan Goldstein and Principal
    Assistant U.S. Attorney Bruce Goldstein); H.R. Res. 647, 94th Cong. (1975) (Ambassador
    to Iran Richard Helms); H.R. Res. 547, 94th Cong. (1975) (Special Crime Strike Force
    Prosecutor Liam Coonan). Others called for an investigation. See, e.g., H.R. Res. 589,
    110th Cong. (2007) (Attorney General Alberto Gonzales); H.R. Res. 582, 105th Cong.
    (1998) (Independent Counsel Kenneth Starr); H.R. Res. 102, 99th Cong. (1985) (Chair-
    man of the Board of Governors of the Federal Reserve System Paul Volcker); H.R. Res.
    101, 99th Cong. (1985) (same and others); H.R. Res. 1025, 95th Cong. (1978) (Attorney
    General Griffin Bell); H.R. Res. 1002, 95th Cong. (1978) (same); H.R. Res. 569, 93d
    30
    House Committees’ Authority to Investigate for Impeachment
    reviewed the matter and considered whether to pursue a formal impeach-
    ment inquiry—it did not treat the referral as stand-alone authorization to
    conduct an investigation. When a committee concluded that the charges
    warranted investigation, it reported to the full House, which then consid-
    ered whether to adopt a resolution to authorize a formal investigation.
    For example, in March 1867, the House approved a resolution directing
    the Committee on Public Expenditures “to inquire into the conduct of
    Henry A. Smythe, collector of the port of New York.” Cong. Globe, 40th
    Cong., 1st Sess. 132 (1867); see also 
    id. (noting that
    the resolution had
    been modified following debate “so as to leave out that part about bring-
    ing articles of impeachment”). Weeks later, the House voted to authorize
    an impeachment investigation. 
    Id. at 290
    (authorizing the investigating
    committee to “send for persons and papers”). The House followed this
    same procedure in 1916 for U.S. Attorney H. Snowden Marshall. H.R.
    Res. 90, 64th Cong. (1916) (initial resolution referred to the Judiciary
    Committee); H.R. Res. 110, 64th Cong. (1916) (resolution approving the
    investigation contemplated in the initial resolution). And the process
    repeated in 1922 for Attorney General Harry Daugherty. H.R. Res. 425,
    67th Cong. (1922) (referring the initial resolution to the committee); H.R.
    Res. 461, 67th Cong. (1922) (resolution approving the investigation
    contemplated in the initial resolution).
    In a few instances, the House asked committees to draft articles of im-
    peachment without calling for any additional impeachment investigation.
    For example, in 1876, after uncovering “unquestioned evidence of the
    malfeasance in office by General William W. Belknap” (who was then
    Secretary of War) in the course of another investigation, the House ap-
    proved a resolution charging the Committee on the Judiciary with the
    responsibility to “prepare and report without unnecessary delay suitable
    articles of impeachment.” 4 Cong. Rec. 1426, 1433 (1876). When a key
    witness left the country, however, the committee determined that addi-
    tional investigation was warranted, and it asked to be authorized “to take
    Cong. (1973) (Vice President Spiro Agnew); H.R. Res. 67, 76th Cong. (1939) (Secretary
    of Labor Frances Perkins and others); 28 Cong. Rec. 114, 126 (1895) (Ambassador to
    Great Britain Thomas Bayard); 16 Cong. Rec. 17−19 (1884) (U.S. Marshal Lot Wright);
    Cong. Globe, 40th Cong., 1st Sess. 778−79 (1867) (Minister to Great Britain Charles
    Francis Adams). On occasion, the House voted to table these resolutions instead of
    referring them to a committee. See, e.g., H.R. Res. 545, 105th Cong. (1998) (resolution of
    impeachment for Independent Counsel Kenneth Starr); H.R. Res. 1267, 95th Cong. (1978)
    (resolution of impeachment for Ambassador to the United Nations Andrew Young).
    31
    Opinions of the Office of Legal Counsel in Volume 44
    further proof ” and “to send for persons and papers” in its search for
    alternative evidence. 
    Id. at 1564,
    1566; see also 3 Hinds’ Precedents
    §§ 2444–45, at 902–04.
    In some cases, the House declined to authorize a committee to investi-
    gate impeachment with the aid of compulsory process. In 1873, the House
    authorized the Judiciary Committee “to inquire whether anything” in
    testimony presented to a different committee implicating Vice President
    Schuyler Colfax “warrants articles of impeachment of any officer of the
    United States not a member of this House, or makes it proper that further
    investigation should be ordered in his case.” Cong. Globe, 42d Cong.,
    3d Sess. 1545 (1873); see 3 Hinds’ Precedents § 2510, at 1016–17.
    No further investigation was authorized. A similar sequence occurred in
    1917 in the case of an impeachment resolution offered against members of
    the Federal Reserve Board. See 54 Cong. Rec. 3126−30 (1917) (im-
    peachment resolution); H.R. Rep. No. 64-1628, at 1 (1917) (noting that
    following the referral of the impeachment resolution, the Committee had
    reviewed available information and determined that no further proceed-
    ings were warranted). In 1932, the House referred to the Judiciary Com-
    mittee a resolution calling for the investigation of the possible impeach-
    ment of Secretary of the Treasury Andrew Mellon. H.R. Res. 92, 72d
    Cong. (1932); see also 3 Deschler’s Precedents ch. 14, § 14.1, at 2134–
    39. The following month, the House approved a resolution discontinuing
    any investigation of the charges. 75 Cong. Rec. 3850 (1932); see also
    3 Deschler’s Precedents ch. 14, § 14.2, at 2139–40.
    Most recently, in the 114th Congress, the House referred to the Judici-
    ary Committee resolutions concerning the impeachment of the Commis-
    sioner of the Internal Revenue Service, John Koskinen. See H.R. Res.
    494, 114th Cong. (2015); H.R. Res. 828, 114th Cong. (2016). Shortly
    after an attempt to force a floor vote on one of the resolutions, Koskinen
    voluntarily appeared before the committee at a hearing. See Impeachment
    Articles Referred on John Koskinen (Part III): Hearing Before the H.
    Comm. on the Judiciary, 114th Cong. 2 (2016). The ranking minority
    member, Representative John Conyers, observed that, despite the title,
    “this is not an impeachment hearing” because, “[a]ccording to parliamen-
    tarians of the House past and present, the impeachment process does
    not begin until the House actually votes to authorize this Committee to
    investigate the charges.” 
    Id. at 3;
    see also 
    id. at 30
    (similar statement by
    Rep. Johnson). During the hearing, Commissioner Koskinen offered to
    provide a list of supporting witnesses who could be cross-examined “if
    32
    House Committees’ Authority to Investigate for Impeachment
    the Committee decided it wanted to go to a full-scale impeachment pro-
    cess, which I understand this is not.” 
    Id. at 45.
    Two months later, one of
    the impeachment resolutions was briefly addressed on the floor of the
    House, and again referred to the Judiciary Committee, but without provid-
    ing any investigative authority. See 162 Cong. Rec. H7251–54 (daily ed.
    Dec. 6, 2016). The committee never sought to compel the appearance of
    Koskinen or any other witness, and the committee does not appear to have
    taken any further action before the Congress expired.
    In his 1978 book on presidential impeachment, former House im-
    peachment attorney John Labovitz observed that there were a “few excep-
    tions,” “mostly in the 1860s and 1870s,” to the general rule that “past
    impeachment investigations ha[ve] been authorized by a specific resolu-
    tion conferring subpoena power.” Labovitz, Presidential Impeachment at
    182 & n.18. In our review of the history, we have identified one case from
    that era where a House committee commenced a legislative oversight
    investigation and subsequently moved, without separate authorization, to
    consider impeachment. 25 But the overwhelming historical practice to the
    contrary confirms the Judiciary Committee’s well-considered conclusions
    in 1974 and 1998 that a committee requires specific authorization from
    the House before it may use compulsory process to investigate for im-
    peachment purposes.
    25 In 1878, the Committee on Expenditures in the State Department, which was
    charged with investigative authority for “the exposing of frauds or abuses of any kind,”
    7 Cong. Rec. 287, 290 (1878), was referred an investigation into maladministration at the
    consulate in Shanghai during the terms of Consul-General George Seward and Vice
    Consul-General O.B. Bradford, 
    id. at 504,
    769. Eventually, the committee began to
    consider Seward’s impeachment, serving him with a subpoena for testimony and docu-
    ments, in response to which he asserted his privilege against self-incrimination. See
    3 Hinds’ Precedents § 2514, at 1023–24; H.R. Rep. No. 45-141, at 1–3 (1879). The
    committee recommended articles of impeachment, but the House declined to act before
    the end of the Congress. See 8 Cong. Rec. 2350–55 (1879); 3 Hinds’ Precedents § 2514,
    at 1025. During this same period, the Committee on Expenditures reported proposed
    articles of impeachment against Bradford but recommended “that the whole subject be
    referred to the Committee on the Judiciary” for further consideration. H.R. Rep. No. 45-
    818, at 7 (1878). The House agreed to the referral, but no further action was taken.
    7 Cong. Rec. at 3667.
    33
    Opinions of the Office of Legal Counsel in Volume 44
    3.
    The House has followed the same practice in connection with nearly all
    impeachment investigations involving federal judges. Committees some-
    times studied initial referrals, but they waited for authorization from the
    full House before conducting any formal impeachment investigation.
    Three cases from the late 1980s departed from that pattern, but the House
    has returned during the past three decades to the historical baseline,
    repeatedly ensuring that the Judiciary Committee had a proper delegation
    for each impeachment investigation.
    The practice of having the House authorize each specific impeachment
    inquiry is reflected in the earliest impeachment investigations involving
    judges. In 1804, the House considered proposals to impeach two judges:
    Samuel Chase, an associate justice of the Supreme Court, and Richard
    Peters, a district judge. See 3 Hinds’ Precedents § 2342, at 711–16. There
    was a “lengthy debate” about whether the evidence was appropriate to
    warrant the institution of an inquiry. 
    Id. at 712.
    The House then adopted
    a resolution appointing a select committee “to inquire into the official
    conduct” of Chase and Peters “and to report” the committee’s “opinion
    whether” either of the judges had “so acted, in their judicial capacity, as
    to require the interposition of the constitutional power of this House.”
    13 Annals of Cong. 850, 875–76 (1804); 3 Hinds’ Precedents § 2342, at
    715. A few days later, another resolution “authorized” the committee “to
    send for persons, papers, and records.” 13 Annals of Cong. at 877; see
    also 3 Hinds’ Precedents § 2342, at 715. At the conclusion of its investi-
    gation, the committee recommended that Chase, but not Peters, be im-
    peached. 3 Hinds’ Precedents § 2343, at 716. The House thereafter agreed
    to a resolution impeaching Chase. 
    Id. at 717.
    Congress recessed before the
    Senate could act, but, during the next Congress, the House appointed an
    almost identical select committee, which was “given no power of investi-
    gation.” 
    Id. §§ 2343–44,
    at 717–18. The committee recommended revised
    articles of impeachment against Chase, which were again adopted by the
    House. 
    Id. § 2344,
    at 718–19. In 1808, the House again separately author-
    ized an investigation when it considered whether Peter Bruin, a Missis-
    sippi territorial judge, should be impeached for “neglect of duty and
    drunkenness on the bench.” 
    Id. § 2487,
    at 983–84. A member of the
    House objected “that it would hardly be dignified for the Congress to
    proceed to an impeachment” based on the territorial legislature’s referral
    and proposed the appointment of a committee “to inquire into the proprie-
    34
    House Committees’ Authority to Investigate for Impeachment
    ty of impeaching.” 
    Id. at 984;
    see 18 Annals of Cong. 2069 (1808). The
    House then passed a resolution forming a committee to conduct an in-
    quiry, which included the “power to send for persons, papers, and rec-
    ords” but, like most inquiries to follow, did not result in impeachment. 18
    Annals of Cong. at 2189; 3 Hinds’ Precedents § 2487, at 984.
    Over the course of more than two centuries thereafter, members of the
    House introduced resolutions to impeach, or to investigate for potential
    impeachment, dozens more federal judges, and the House continued,
    virtually without exception, to provide an express authorization before
    any committee proceeded to exercise investigative powers. 26 In one 1874
    case, the Judiciary Committee realized only after witnesses had traveled
    from Arkansas that it could not find any resolution granting it compulsory
    powers to investigate previously referred charges against Judge William
    Story. See 2 Cong. Rec. 1825, 3438 (1874); 3 Hinds’ Precedents § 2513,
    at 1023. In order to “cure” that “defect,” the committee reported a privi-
    leged resolution to the floor of the House that would grant the committee
    “power to send for persons and papers” as part of the impeachment inves-
    26See, e.g., 3 Hinds’ Precedents § 2489, at 986 (William Van Ness, Mathias
    Tallmadge, and William Stephens, 1818); 
    id. § 2490,
    at 987 (Joseph Smith, 1825); 
    id. § 2364,
    at 774 (James Peck, 1830); 
    id. § 2492,
    at 990 (Alfred Conkling, 1830); 
    id. § 2491,
    at 989 (Buckner Thurston, 1837); 
    id. § 2494,
    at 993–94 (P.K. Lawrence, 1839); 
    id. §§ 2495,
    2497, 2499, at 994, 998, 1003 (John Watrous, 1852–60); 
    id. § 2500,
    at 1005
    (Thomas Irwin, 1859); 
    id. § 2385,
    at 805 (West Humphreys, 1862); 
    id. § 2503,
    at 1008
    (anonymous justice of the Supreme Court, 1868); 
    id. § 2504,
    at 1008–09 (Mark Delahay,
    1872); 
    id. § 2506,
    at 1011 (Edward Durell, 1873); 
    id. § 2512,
    at 1021 (Richard Busteed,
    1873); 
    id. § 2516,
    at 1027 (Henry Blodgett, 1879); 
    id. §§ 2517–18,
    at 1028, 1030–31
    (Aleck Boarman, 1890–92); 
    id. § 2519,
    at 1032 (J.G. Jenkins, 1894); 
    id. § 2520,
    at 1033
    (Augustus Ricks, 1895); 
    id. § 2469,
    at 949–50 (Charles Swayne, 1903); 6 Clarence
    Cannon, Cannon’s Precedents of the House of Representatives of the United States § 498,
    at 685 (1936) (Robert Archbald, 1912); 
    id. § 526,
    at 746–47 (Cornelius H. Hanford,
    1912); 
    id. § 527,
    at 749 (Emory Speer, 1913); 
    id. § 528,
    at 753 (Daniel Wright, 1914); 
    id. § 529,
    at 756 (Alston Dayton, 1915); 
    id. § 543,
    at 777–78 (William Baker, 1924); 
    id. § 544,
    at 778–79 (George English, 1925); 
    id. § 549,
    at 789–90 (Frank Cooper, 1927); 
    id. § 550,
    at 791–92 (Francis Winslow, 1929); 
    id. § 551,
    at 793 (Harry Anderson, 1930); 
    id. § 552,
    at 794 (Grover Moscowitz, 1930); 
    id. § 513,
    at 709–10 (Harold Louderback, 1932);
    3 Deschler’s Precedents ch. 14, § 14.4, at 2143 (James Lowell, 1933); 
    id. § 18.1,
    at 2205–
    06 (Halsted Ritter, 1933); 
    id. § 14.10,
    at 2148 (Albert Johnson and Albert Watson, 1944);
    H.R. Res. 1066, 94th Cong. (1976) (certain federal judges); H.R. Res. 966, 95th Cong.
    (1978) (Frank Battisti); see also 51 Cong. Rec. 6559–60 (1914) (noting passage of
    authorizing resolution for investigation of Daniel Wright); 68 Cong. Rec. 3532 (1927)
    (same for Frank Cooper).
    35
    Opinions of the Office of Legal Counsel in Volume 44
    tigation. 2 Cong. Rec. at 3438. The House promptly agreed to the resolu-
    tion, enabling the committee to “examine” the witnesses that day. 
    Id. In other
    cases, however, no full investigation ever materialized. In
    1803, John Pickering, a district judge, was impeached, but the House
    voted to impeach him without conducting any investigation at all, relying
    instead upon documents supplied by President Jefferson. See 3 Hinds’
    Precedents § 2319, at 681–82; see also Lynn W. Turner, The Impeach-
    ment of John Pickering, 54 Am. Hist. Rev. 485, 491 (1949). Sometimes,
    the House authorized only a preliminary inquiry to determine whether an
    investigation would be warranted. In 1908, for instance, the House asked
    the Judiciary Committee to consider proposed articles impeaching Judge
    Lebbeus Wilfley of the U.S. Court for China. In the ensuing hearing, the
    Representative who had introduced the resolution acknowledged that the
    committee was not “authorized to subpoena witnesses” and had been
    authorized to conduct only “a preliminary examination,” which was “not
    like an investigation ordinarily held by the House,” but was instead dedi-
    cated solely to determining “whether you believe it is a case that ought to
    be investigated at all.” 27 In many other cases, it is apparent that—even
    when impeachment resolutions had been referred to them—committees
    conducted no formal investigation. 28
    27 Articles for the Impeachment of Lebbeus R. Wilfley, Judge of the U.S. Court for Chi-
    na: Hearings Before a Subcomm. of the H. Comm. on the Judiciary, 60th Cong. 4 (1908)
    (statement of Rep. Waldo); see also 
    id. at 45–46
    (statement of Rep. Moon) (“This com-
    mittee conceives to be its duty solely, under the resolution referring this matter to them, to
    examine the charges preferred in the petition . . . and to report thereon whether in its
    judgement the petitioner has made out a prima facie case; and also whether . . . Congress
    should adopt a resolution instructing the Judiciary Committee to proceed to an investiga-
    tion of the facts of the case.”); 6 Cannon’s Precedents § 525, at 743–45 (summarizing the
    Wilfley case, in which the Judiciary Committee ultimately reported that no formal
    investigation was warranted). The case of Judge Samuel Alschuler in 1935 similarly
    involved only a preliminary investigation—albeit one with actual investigative powers.
    The House first referred to the Judiciary Committee a resolution that, if approved, would
    authorize an investigation of potential impeachment charges. See 79 Cong. Rec. 7086,
    7106 (1935). Six days later, it adopted a resolution that granted the committee investiga-
    tive powers in support of “the preliminary examinations deemed necessary” for the
    committee to make a recommendation about whether a full investigation should occur. 
    Id. at 7393–94.
    The committee ultimately recommended against a full investigation. See H.R.
    Rep. No. 74-1802, at 2 (1935).
    28 See, e.g., 18 Annals of Cong. 1885–86, 2197–98 (1808) (Harry Innes, 1808; the
    House passed a resolution authorizing an impeachment investigation, which concluded
    36
    House Committees’ Authority to Investigate for Impeachment
    In 1970, in a rhetorical departure from well-established practice, a sub-
    committee of the Judiciary Committee described itself as investigating the
    impeachment of Justice William O. Douglas based solely upon an impeach-
    ment resolution referred to the Judiciary Committee. See 116 Cong. Rec.
    11920, 11942 (1970); 3 Deschler’s Precedents ch. 14, §§ 14.14−14.16, at
    2151−64; see also Labovitz, Presidential Impeachment at 182 n.18 (not-
    ing that “[t]he Douglas inquiry was the first impeachment investigation in
    twenty-five years, and deviation from the older procedural pattern was not
    surprising”). Yet, the subcommittee did not resort to any compulsory
    process during its inquiry, and it did not recommend impeachment.
    3 Deschler’s Precedents ch. 14, §§ 14.15−14.16, at 2158−63. According-
    ly, the committee did not actually exercise any of the investigative powers
    of the House.
    In the late 1980s, the House Judiciary Committee considered the im-
    peachment of three district-court judges without any express authorization
    from the House: Walter Nixon, Alcee Hastings, and Harry Claiborne. See
    In re Application of the Comm. on the Judiciary, 
    2019 WL 5485221
    , at
    *26 (discussing these investigations). All three judges had been criminally
    prosecuted, and two had been convicted. See H.R. Rep. No. 101-36, at
    12–13 (1989) (describing Nixon’s prosecution and conviction); H.R. Rep.
    No. 100-810, at 7−8, 29–31, 38–39 (1988) (describing Hastings’s indict-
    ment and trial and the subsequent decision to proceed with a judicial-
    misconduct proceeding in lieu of another prosecution); H.R. Rep. No. 99-
    688, at 9, 17–20 (1986) (describing Claiborne’s prosecution and convic-
    tion). In the Claiborne inquiry, the committee does not appear to have
    that the evidence accompanying the resolution did not support impeachment); 3 Hinds’
    Precedents § 2486, at 981–83 (George Turner, 1796; no apparent investigation, presuma-
    bly because of the parallel criminal prosecution recommended by Attorney General Lee,
    as discussed above); 
    id. § 2488,
    at 985 (Harry Toulmin, 1811; the House “declined to
    order a formal investigation”); 40 Annals of Cong. 463–69, 715–18 (1822–23) (Charles
    Tait, 1823; no apparent investigation beyond examination of documents containing
    charges); 3 Hinds’ Precedents § 2493, at 991–92 (Benjamin Johnson, 1833; no apparent
    investigation); 
    id. § 2511,
    at 1019–20 (Charles Sherman, 1873; the Judiciary Committee
    received evidence from the Ways and Means Committee, which had been investigating
    corruption in Congress, but the Judiciary Committee conducted no further investigation);
    6 Cannon’s Precedents § 535, at 769 (Kenesaw Mountain Landis, 1921; the Judiciary
    Committee reported that “charges were filed too late in the present session of the Con-
    gress” to enable investigation); 3 Deschler’s Precedents ch. 14, § 14.6, at 2144–45
    (Joseph Molyneaux, 1934; the Judiciary Committee took no action on the referral of a
    resolution that would have authorized an investigation).
    37
    Opinions of the Office of Legal Counsel in Volume 44
    issued any subpoenas. See H.R. Rep. No. 99-688, at 4 (noting that the
    committee sent “[i]nvitational letters to all witnesses,” who apparently
    cooperated to the Committee’s satisfaction). The committee did issue
    subpoenas in the Nixon and Hastings investigations, yet no witness ap-
    pears to have objected on the ground that the committee lacked jurisdic-
    tion to issue the subpoenas, and at least one witness appears to have
    requested a subpoena. 29 In those two cases, though, the Judiciary Commit-
    tee effectively compelled production without any express authorization
    from the House. 30
    In the years after these outliers, the Judiciary Committee returned to the
    practice of seeking specific authorization from the House before conduct-
    ing impeachment investigations. Most notably, as discussed above, the
    Judiciary Committee “decided that it must receive authorization from the
    full House before proceeding” with an impeachment investigation of
    President Clinton. H.R. Rep. No. 105-795, at 24 (emphasis added). And
    the House has used the same practice with respect to federal judges. 31
    Thus, in 2008, the House adopted a resolution authorizing the Judiciary
    Committee to investigate the impeachment of Judge G. Thomas Porteous,
    Jr., including the grant of subpoena authority. See H.R. Rep. No. 111-427,
    at 7 (2010); H.R. Res. 1448, 110th Cong. (2008); 154 Cong. Rec. 19502
    (2008). After the Congress expired, the House in the next Congress
    29 See H.R. Rep. No. 100-810, at 11 & n.14 (stating that, in the Hastings investigation,
    a committee subpoena had been issued for William Borders, who challenged the subpoena
    on First, Fourth, Fifth, and Eighth Amendment grounds); H.R. Rep. No. 100-1124, at 130
    (1989) (noting the issuance of “subpoenas duces tecum” in the investigation of Judge
    Nixon); 134 Cong. Rec. 27782 (1988) (statement of Rep. Edwards) (explaining the
    subcommittee’s need to depose some witnesses pursuant to subpoena in the Nixon
    investigation); Judge Walter L. Nixon, Jr., Impeachment Inquiry: Hearing Before the
    Subcomm. on Civil & Constitutional Rights of the H. Comm. on the Judiciary, 101st
    Cong. 530–606 (1988) (reprinting deposition of Magistrate Judge Roper).
    30 The House did pass resolutions authorizing funds for investigations with respect to
    the Hastings impeachment, see H.R. Res. 134, 100th Cong. (1987); H.R. Res. 388, 100th
    Cong. (1988), and resolutions authorizing the committee to permit its counsel to take
    affidavits and depositions in both the Nixon and Hastings impeachments, see H.R. Res.
    562, 100th Cong. (1988) (Nixon); H.R. Res. 320, 100th Cong. (1987) (Hastings).
    31 In the post-1989 era, as before, most of the impeachment resolutions against judges
    that were referred to the Judiciary Committee did not result in any further investigation.
    See, e.g., H.R. Res. 916, 109th Cong. (2006) (Manuel Real); H.R. Res. 207, 103d Cong.
    (1993) (Robert Collins); H.R. Res. 177, 103d Cong. (1993) (Robert Aguilar); H.R. Res.
    176, 103d Cong. (1993) (Robert Collins).
    38
    House Committees’ Authority to Investigate for Impeachment
    adopted a new resolution re-authorizing the inquiry, again with subpoena
    authority. See H.R. Res. 15, 111th Cong. (2009); 155 Cong. Rec. 568, 571
    (2009). Several months later, another district judge, Samuel Kent, pleaded
    guilty to obstruction of justice and was sentenced to 35 months of incar-
    ceration. See H.R. Rep. 111-159, at 9–13 (2009). The House then adopted
    a resolution directing the Judiciary Committee to investigate impeach-
    ment, again specifically granting subpoena authority. See 
    id. at 13;
    H.R.
    Res. 424, 111th Cong. (2009); 155 Cong. Rec. at 12211–13.
    Thus, the House’s long-standing and nearly unvarying practice with
    respect to judicial impeachment inquiries is consistent with the conclusion
    that the power to investigate in support of the House’s “sole Power of
    Impeachment,” U.S. Const. art. I, § 2, cl. 5, may not be exercised by a
    committee without an express delegation from the House. In the cases of
    Judges Nixon and Hastings, the Judiciary Committee did exercise com-
    pulsory authority despite the absence of any delegation from the House.
    But insofar as no party challenged the committee’s authority at the time,
    and no court addressed the matter, these historical outliers do not under-
    mine the broader constitutional principle. As the Supreme Court observed
    in Noel Canning, “when considered against 200 years of settled practice,”
    a “few scattered examples” are rightly regarded “as 
    anomalies.” 573 U.S. at 538
    . They do not call into question the soundness of the House’s oth-
    erwise consistent historical practice, much less the constitutional require-
    ment that a committee exercise the constitutional powers of the House
    only with an express delegation from the House itself.
    III.
    Having concluded that a House committee may not conduct an im-
    peachment investigation without a delegation of authority, we next con-
    sider whether the House provided such a delegation to the Foreign Affairs
    Committee or to the other committees that issued subpoenas pursuant to
    the asserted impeachment inquiry. During the five weeks between the
    Speaker’s announcement on September 24 and the adoption of Resolution
    660 on October 31, the committees issued numerous impeachment-related
    subpoenas. 
    See supra
    note 9. We therefore provided advice during that
    period about whether any of the committees had authority to issue those
    subpoenas. Because the House had not adopted an impeachment resolu-
    tion, the answer to that question turned on whether the committees could
    issue those subpoenas based upon any preexisting subpoena authority.
    39
    Opinions of the Office of Legal Counsel in Volume 44
    In justifying the subpoenas, the Foreign Affairs Committee and other
    committees pointed to the resolution adopting the Rules of the House of
    Representatives, which establish the committees and authorize investiga-
    tions for matters within their jurisdiction. The committees claimed that
    Rule XI confers authority to issue subpoenas in connection with an im-
    peachment investigation. Although the House has expanded its commit-
    tees’ authority in recent decades, the House Rules continue to reflect the
    long-established distinction between legislative and non-legislative inves-
    tigative powers. Those rules confer legislative oversight jurisdiction on
    committees and authorize the issuance of subpoenas to that end, but they
    do not grant authority to investigate for impeachment purposes. While the
    House committees could have sought some information relating to the
    same subjects in the exercise of their legislative oversight authority, the
    subpoenas they purported to issue “pursuant to the House of Representa-
    tives’ impeachment inquiry” were not in support of such oversight. We
    therefore conclude that they were unauthorized.
    A.
    The standing committees of the House trace their general subpoena
    powers back to the House Rules, which the 116th Congress adopted by
    formal resolution. See H.R. Res. 6, 116th Cong. (2019). The House Rules
    are more than 60,000 words long, but they do not include the word “im-
    peachment.” The Rules’ silence on that topic is particularly notable when
    contrasted with the Senate, which has adopted specific “Rules of Pro-
    cedure and Practice” for impeachment trials. S. Res. 479, 99th Cong.
    (1986). 32 The most obvious conclusion to draw from that silence is that
    the current House, like its predecessors, retained impeachment authority
    at the level of the full House, subject to potential delegations in resolu-
    tions tailored for that purpose.
    Rule XI of the Rules of the House affirmatively authorizes committees
    to issue subpoenas, but only for matters within their legislative jurisdic-
    tion. The provision has been a part of the House Rules since 1975. See
    H.R. Res. 988, 93d Cong. § 301 (1974). Clause 2(m)(1) of Rule XI vests
    32Unlike the House, “the Senate treats its rules as remaining in effect continuously
    from one Congress to the next without having to be re-adopted.” Richard S. Beth, Cong.
    Research Serv., R42929, Procedures for Considering Changes in Senate Rules 9 (Jan. 22,
    2013). Of course, like the House, the Senate may change its rules by simple resolution.
    40
    House Committees’ Authority to Investigate for Impeachment
    each committee with the authority to issue subpoenas “[f ]or the purpose
    of carrying out any of its functions and duties under this rule and rule X
    (including any matters referred to it under clause 2 of rule XII).” Rule XI,
    cl. 2(m)(1); see also Rule X, cl. 11(d)(1) (making clause 2 of Rule XI
    applicable to HPSCI). The committees therefore have subpoena power to
    carry out their authorities under three rules: Rule X, Rule XI, and clause 2
    of Rule XII.
    Rule X does not provide any committee with jurisdiction over im-
    peachment. Rule X establishes the “standing committees” of the House
    and vests them with “their legislative jurisdictions.” Rule X, cl. 1. The
    jurisdiction of each committee varies in subject matter and scope. While
    the Committee on Ethics, for example, has jurisdiction over only “[t]he
    Code of Official Conduct” (Rule X, cl. 1(g)), the jurisdiction of the For-
    eign Affairs Committee spans seventeen subjects, including “[r]elations of
    the United States with foreign nations generally,” “[i]ntervention abroad
    and declarations of war,” and “[t]he American National Red Cross” (Rule
    X, cl. 1(i)(1), (9), (15)). The rule likewise spells out the jurisdiction of the
    Committee on Oversight and Reform (Rule X, cl. 1(n), cl. 3(i)), and the
    jurisdiction of the Judiciary Committee (Rule X, cl. 1(l )). Clause 11 of
    Rule X establishes HPSCI and vests it with jurisdiction over “[t]he Cen-
    tral Intelligence Agency, the Director of National Intelligence, and the
    National Intelligence Program” and over “[i]ntelligence and intelligence-
    related activities of all other departments and agencies.” Rule X, cl.
    11(a)(1), (b)(1)(A)–(B).
    The text of Rule X confirms that it addresses the legislative jurisdiction
    of the standing committees. After defining each standing committee’s
    subject-matter jurisdiction, the Rule provides that “[t]he various standing
    committees shall have general oversight responsibilities” to assist the
    House in its analysis of “the application, administration, execution, and
    effectiveness of Federal laws” and of the “conditions and circumstances
    that may indicate the necessity or desirability of enacting new or addition-
    al legislation,” as well as to assist the House in its “formulation, consider-
    ation, and enactment of changes in Federal laws, and of such additional
    legislation as may be necessary or appropriate.” Rule X, cl. 2(a)(1)–(2).
    The committees are to conduct oversight “on a continuing basis” “to
    determine whether laws and programs addressing subjects within the
    jurisdiction of a committee” are implemented as Congress intends “and
    whether they should be continued, curtailed, or eliminated.” Rule X, cl.
    2(b)(1). Those are all functions traditionally associated with legislative
    41
    Opinions of the Office of Legal Counsel in Volume 44
    oversight, not the separate power of impeachment. 
    See supra
    Part II.A.
    Clause 3 of Rule X further articulates “[s]pecial oversight functions” with
    respect to particular subjects for certain committees; for example, the
    Committee on Foreign Affairs “shall review and study on a continuing
    basis laws, programs, and Government activities relating to . . . intelli-
    gence activities relating to foreign policy,” Rule X, cl. 3(f ). And clause 4
    addresses “[a]dditional functions of committees,” including functions
    related to the review of appropriations and the special authorities of the
    Committee on Oversight and Reform, Rule X, cl. 4(a)(1), (c)(1). But none
    of the “[s]pecial oversight” or “[a]dditional” functions specified in clauses
    3 and 4 includes any reference to the House’s impeachment power.
    The powers of HPSCI are addressed in clause 11 of Rule X. Unlike the
    standing committees, HPSCI is not given “[g]eneral oversight responsibil-
    ities” in clause 2. But clause 3 gives it the “[s]pecial oversight functions”
    of “review[ing] and study[ing] on a continuing basis laws, programs, and
    activities of the intelligence community” and of “review[ing] and
    study[ing] . . . the sources and methods of ” specified entities that engage
    in intelligence activities. Rule X, cl. 3(m). And clause 11 further provides
    that proposed legislation about intelligence activities will be referred to
    HPSCI and that HPSCI shall report to the House “on the nature and extent
    of the intelligence and intelligence-related activities of the various de-
    partments and agencies of the United States.” Rule X, cl. 11(b)(1), (c)(1);
    see also H.R. Res. 658, 95th Cong. § 1 (1977) (resolution establishing
    HPSCI, explaining its purpose as “provid[ing] vigilant legislative over-
    sight over the intelligence and intelligence-related activities of the United
    States” (emphasis added)). Again, those powers sound in legislative
    oversight, and nothing in the Rules suggests that HPSCI has any generic
    delegation of the separate power of impeachment.
    Consistent with the foregoing textual analysis, Rule X has been seen as
    conferring legislative oversight authority on the House’s committees,
    without any suggestion that impeachment authorities are somehow in-
    cluded therein. The Congressional Research Service describes Rule X as
    “contain[ing] the legislative and oversight jurisdiction of each standing
    committee, several clauses on committee procedures and operations, and a
    clause specifically addressing the jurisdiction and operation of the Perma-
    nent Select Committee on Intelligence.” Michael L. Koempel & Judy
    Schneider, Cong. Research Serv., R41605, House Standing Committees’
    Rules on Legislative Activities: Analysis of Rules in Effect in the 114th
    Congress 2 (Oct. 11, 2016); see also Dolan, Congressional Oversight
    42
    House Committees’ Authority to Investigate for Impeachment
    Manual at 25 (distinguishing a committee inquiry with “a legislative
    purpose” from inquiries conducted under “some other constitutional
    power of Congress, such as the authority” to “conduct impeachment
    proceedings”). In the chapter of Deschler’s Precedents devoted to ex-
    plaining the “[i]nvestigations and [i]nquiries” by the House and its com-
    mittees, the Parliamentarian repeatedly notes that impeachment investi-
    gations and other non-legislative powers are discussed elsewhere. See
    4 Deschler’s Precedents ch. 15, § 1, at 2283; 
    id. § 14,
    at 2385 n.12; 
    id. § 16,
    at 2403 & n.4.
    Rule X concerns only legislative oversight, and Rule XI does not ex-
    pand the committees’ subpoena authority any further. That rule rests upon
    the jurisdiction granted in Rule X. See Rule XI, cl. 1(b)(1) (“Each com-
    mittee may conduct at any time such investigations and studies as it
    considers necessary or appropriate in the exercise of its responsibilities
    under rule X.”). Nor does Rule XII confer any additional jurisdiction.
    Clause 2(a) states that “[t]he Speaker shall refer each bill, resolution, or
    other matter that relates to a subject listed under a standing committee
    named in clause 1 of rule X[.]” Rule XII, cl. 2(a). The Speaker’s referral
    authority under Rule XII is thus limited to matters within a committee’s
    Rule X legislative jurisdiction. See 18 Deschler’s Precedents app. at 578
    (“All committees were empowered by actual language of the Speaker’s
    referral to consider only ‘such provisions of the measure as fall within
    their respective jurisdictions under Rule X.’”). Accordingly, the Speaker
    may not expand the jurisdiction of a committee by referring a bill or
    resolution falling outside the committee’s Rule X authority. 33
    In reporting Resolution 660 to the House, the Rules Committee ex-
    pressed the view that clause 2(m) of Rule XI gave standing committees
    the authority to issue subpoenas in support of impeachment inquiries. See
    H.R. Rep. No. 116-266, at 18 (2019). But the committee did not explain
    which terms of the rule provide such authority. To the contrary, the com-
    mittee simply asserted that the rule granted such authority and that the
    text of Resolution 660 departed from its predecessors on account of
    amendments to clause 2(m) that were adopted after the “Clinton and
    33 Nor do the Rules otherwise give the Speaker the authority to order an investigation
    or issue a subpoena in connection with impeachment. Rule I sets out the powers of the
    Speaker. She “shall sign . . . all writs, warrants, and subpoenas of, or issued by order of,
    the House.” Rule I, cl. 4. But that provision applies only when the House itself issues an
    order. See Jefferson’s Manual § 626, at 348.
    43
    Opinions of the Office of Legal Counsel in Volume 44
    Nixon impeachment inquiry resolutions.” 
    Id. Yet clause
    2(m) of Rule XI
    was adopted two decades before the Clinton inquiry. 34 Even with that
    authority in place, the Judiciary Committee recognized in 1998 that it
    “must receive authorization from the full House before proceeding” to
    investigate President Clinton for impeachment purposes. H.R. Rep. No.
    105-795, at 24 (emphasis added). And, even before Rule XI was adopted,
    the House had conferred on the Judiciary Committee a materially similar
    form of investigative authority (including subpoena power) in 1973. 35 The
    Judiciary Committee nevertheless recognized that those subpoena powers
    did not authorize it to conduct an impeachment inquiry about President
    Nixon. In other words, the Rules Committee’s recent interpretation of
    clause 2(m) (which it did not explain in its report) cannot be reconciled
    with the Judiciary Committee’s well-reasoned conclusion, in both 1974
    and 1998, that Rule XI (and its materially similar predecessor) do not
    confer any standing authority to conduct an impeachment investigation.
    In modern practice, the Speaker has referred proposed resolutions call-
    ing for the impeachment of a civil officer to the Judiciary Committee.
    See Jefferson’s Manual § 605, at 324. Consistent with this practice, the
    Speaker referred the Sherman resolution (H.R. Res. 13, 116th Cong.) to
    the Judiciary Committee, because it called for the impeachment of Presi-
    dent Trump. Yet the referral itself did not grant authority to conduct an
    impeachment investigation. House committees have regularly received
    referrals and conducted preliminary inquiries, without compulsory pro-
    34 Clause 2(m) of Rule XI was initially adopted on October 8, 1974, and took effect on
    January 3, 1975. See H.R. Res. 988, 93d Cong. The rule appears to have remained materi-
    ally unchanged from 1975 to the present (including during the time of the Clinton investi-
    gation). See H.R. Rule XI, cl. 2(m), 105th Cong. (Jan. 1, 1998) (version in effect during
    the Clinton investigation); Jefferson’s Manual § 805, at 586–89 (reprinting current
    version and describing the provision’s evolution).
    35 At the start of the 93rd Congress in 1973, the Judiciary Committee was “authorized
    to conduct full and complete studies and investigations and make inquiries within its
    jurisdiction as set forth in [the relevant provision] of the Rules of the House of Represent-
    atives” and was empowered “to hold such hearings and require, by subpena or otherwise,
    the attendance and testimony of such witnesses and the production of such books, records,
    correspondence, memorandums, papers, and documents, as it deems necessary.” H.R. Res.
    74, 93d Cong. §§ 1, 2(a) (1973); see also Cong. Research Serv., R45769, The Impeach-
    ment Process in the House of Representatives 4 (updated Nov. 14, 2019) (noting that,
    before Rule XI vested subpoena power in standing committees, the Judiciary Committee
    and other committees had often been given subpoena authority “through resolutions
    providing blanket investigatory authorities that were agreed to at the start of a Congress”).
    44
    House Committees’ Authority to Investigate for Impeachment
    cess, for the purpose of determining whether to recommend that the
    House open a formal impeachment investigation. 
    See supra
    Part II.C.
    Should a committee determine that a formal inquiry is warranted, then the
    committee recommends that the House adopt a resolution that authorizes
    such an investigation, confers subpoena power, and provides special
    process to the target of the investigation. The Judiciary Committee fol-
    lowed precisely that procedure in connection with the impeachment
    investigations of Presidents Nixon and Clinton, among many others. By
    referring an impeachment resolution to the House Judiciary Committee,
    the Speaker did not expand that committee’s subpoena authority to cover
    a formal impeachment investigation. In any event, no impeachment reso-
    lution was ever referred to the Foreign Affairs Committee, HPSCI, or the
    Committee on Oversight and Reform. Rule XII thus could not provide any
    authority to those committees in support of the impeachment-related
    subpoenas issued before October 31.
    Accordingly, when those subpoenas were issued, the House Rules did
    not provide authority to any of those committees to issue subpoenas in
    connection with potential impeachment. In reaching this conclusion, we
    do not question the broad authority of the House of Representatives to
    determine how and when to conduct its business. See U.S. Const. art. I,
    § 5, cl. 2. As the Supreme Court has recognized, “‘all matters of method
    are open to the determination’” of the House, “as long as there is ‘a rea-
    sonable relation between the mode or method of proceeding established
    by the rule and the result which is sought to be attained,’ and the rule does
    not ‘ignore constitutional restraints or violate fundamental rights.’” Noel
    
    Canning, 573 U.S. at 551
    (quoting United States v. Ballin, 
    144 U.S. 1
    , 5
    (1892)). The question, however, is not “what rules Congress may estab-
    lish for its own governance,” but “rather what rules the House has estab-
    lished and whether they have been followed.” Christoffel v. United States,
    
    338 U.S. 84
    , 88–89 (1949); see also Yellin v. United States, 
    374 U.S. 109
    ,
    121 (1963) (stating that a litigant “is at least entitled to have the Commit-
    tee follow its rules and give him consideration according to the standards
    it has adopted in” the relevant rule); United States v. Smith, 
    286 U.S. 6
    , 33
    (1932) (“As the construction to be given to the rules affects persons other
    than members of the Senate, the question presented is of necessity a
    judicial one.”). Statements by the Speaker or by committee chairmen are
    not statements of the House itself. Cf. Noel 
    Canning, 573 U.S. at 552
    –53
    (relying on statements and actions of the Senate itself, as reflected in the
    Journal of the Senate and the Congressional Record, to determine when
    45
    Opinions of the Office of Legal Counsel in Volume 44
    the Senate was “in session”). Our conclusion here turned upon nothing
    more, and nothing less, than the rules and resolutions that had been adopt-
    ed by a majority vote of the full House. 36
    The text of those provisions determined whether the House had dele-
    gated the necessary authority. See 
    id. at 552
    (“[O]ur deference to the
    Senate cannot be absolute. When the Senate is without the capacity to act,
    under its own rules, it is not in session even if it so declares.”). Thus, the
    Supreme Court has repeatedly made clear that a target of the House’s
    compulsory process may question whether a House resolution has actually
    conferred the necessary powers upon a committee, because the commit-
    tee’s “right to exact testimony and to call for the production of documents
    must be found in [the resolution’s] language.” 
    Rumely, 345 U.S. at 44
    ; see
    also 
    Watkins, 354 U.S. at 201
    . In Rumely, the Court expressly rejected the
    argument that the House had confirmed the committee’s jurisdiction by
    adopting a resolution that merely held the witness in contempt after the
    fact. As the Court explained, what was said “after the controversy had
    arisen regarding the scope of the resolution . . . had the usual infirmity of
    post litem motam, self-serving 
    declarations.” 345 U.S. at 48
    . In other
    words, even a vote of the full House could not “enlarge[]” a committee’s
    authority after the fact for purposes of finding that a witness had failed to
    comply with the obligations imposed by the subpoena. 
    Id. Here, the
    House committees claiming to investigate impeachment is-
    sued subpoenas before they had received any actual delegation of im-
    peachment-related authority from the House. Before October 31, the
    committees relied solely upon statements of the Speaker, the committee
    chairmen, and the Judiciary Committee, all of which merely asserted that
    one or more House committees had already been conducting a formal
    impeachment inquiry. There was, however, no House resolution actually
    delegating such authority to any committee, let alone one that did so with
    36 The Judiciary Committee has also invoked House Resolution 430 as an independent
    source of authority for an impeachment inquiry. See Tr. of Mot. Hrg. at 91–92, In re
    Application of the Comm. on the Judiciary; see also Majority Staff of H. Comm. on the
    Judiciary, 116th Cong., Constitutional Grounds for Presidential Impeachment 39 (Dec.
    2019). As discussed above, however, that resolution did not confer any investigative
    authority. Rather, it granted “any and all necessary authority under Article I” only “in
    connection with” certain “judicial proceeding[s]” in federal court. H.R. Res. 430, 116th
    Cong. (2019); see supra note 7. The resolution therefore had no bearing on any commit-
    tee’s authority to compel the production of documents or testimony in an impeachment
    investigation.
    46
    House Committees’ Authority to Investigate for Impeachment
    “sufficient particularity” to compel witnesses to respond. 
    Watkins, 354 U.S. at 201
    ; cf. Gojack v. United States, 
    384 U.S. 702
    , 716–17 (1966). At
    the opening of this Congress, the House had not chosen to confer investi-
    gative authority over impeachment upon any committee, and therefore, no
    House committee had authority to compel the production of documents or
    testimony in furtherance of an impeachment inquiry that it was not au-
    thorized to conduct.
    B.
    Lacking a delegation from the House, the committees could not compel
    the production of documents or the testimony of witnesses for purposes of
    an impeachment inquiry. Because the first impeachment-related subpoena
    —the September 27 subpoena from the Foreign Affairs Committee—
    rested entirely upon the purported impeachment inquiry, see Three
    Chairmen’s Letter, supra note 2, at 1, it was not enforceable. See, e.g.,
    
    Rumely, 345 U.S. at 44
    . Perhaps recognizing this infirmity, the committee
    chairmen invoked not merely the impeachment inquiry in connection with
    subsequent impeachment-related subpoenas but also the committees’
    “oversight and legislative jurisdiction.” 
    See supra
    note 9 and accompany-
    ing text. That assertion of dual authorities presented the question whether
    the committees could leverage their oversight jurisdiction to require the
    production of documents and testimony that the committees avowedly
    intended to use for an unauthorized impeachment inquiry. We advised
    that, under the circumstances of these subpoenas, the committees could
    not do so.
    Any congressional inquiry “must be related to, and in furtherance of, a
    legitimate task of the Congress.” 
    Watkins, 354 U.S. at 187
    . The Executive
    Branch need not presume that such a purpose exists or accept a “make-
    weight” assertion of legislative jurisdiction. Mazars 
    USA, 940 F.3d at 725
    –26, 727; see also Shelton v. United States, 
    404 F.2d 1292
    , 1297 (D.C.
    Cir. 1968) (“In deciding whether the purpose is within the legislative
    function, the mere assertion of a need to consider ‘remedial legislation’
    may not alone justify an investigation accompanied with compulsory
    process[.]”). Indeed, “an assertion from a committee chairman may not
    prevent the Executive from confirming the legitimacy of an investigative
    request.” Congressional Committee’s Request for the President’s Tax
    Returns Under 26 U.S.C. § 6103( f ), 43 Op. O.L.C. __, at *20 (June 13,
    2019). To the contrary, “a threshold inquiry that should be made upon
    47
    Opinions of the Office of Legal Counsel in Volume 44
    receipt of any congressional request for information is whether the request
    is supported by any legitimate legislative purpose.” Response to Congres-
    sional Requests for Information Regarding Decisions Made Under the
    Independent Counsel Act, 
    10 Op. O.L.C. 68
    , 74 (1986); see also Congres-
    sional Requests for Confidential Executive Branch Information, 13 Op.
    O.L.C. 153, 159 (1989) (recognizing that the constitutionally mandated
    accommodation process “requires that each branch explain to the other
    why it believes its needs to be legitimate”).
    Here, the committee chairmen made clear upon issuing the subpoenas
    that the committees were interested in the requested materials to support
    an investigation into the potential impeachment of the President, not to
    uncover information necessary for potential legislation within their re-
    spective areas of legislative jurisdiction. In marked contrast with routine
    oversight, each of the subpoenas was accompanied by a letter signed by
    the chairs of three different committees, who transmitted a subpoena
    “[p]ursuant to the House of Representatives’ impeachment inquiry” and
    recited that the documents would “be collected as part of the House’s
    impeachment inquiry,” and that they would be “shared among the Com-
    mittees, as well as with the Committee on the Judiciary as appropriate.”
    
    See supra
    note 9 and accompanying text. Apart from their token invoca-
    tions of “oversight and legislative jurisdiction,” the letters offered no hint
    of any legislative purpose. The committee chairmen were therefore seek-
    ing to do precisely what they said—compel the production of information
    to further an impeachment inquiry.
    In reaching this conclusion, we do not foreclose the possibility that the
    Foreign Affairs Committee or the other committees could have issued
    similar subpoenas in the bona fide exercise of their legislative oversight
    jurisdiction, in which event the requests would have been evaluated
    consistent with the long-standing confidentiality interests of the Executive
    Branch. See 
    Watkins, 354 U.S. at 187
    (recognizing that Congress’s gen-
    eral investigative authority “comprehends probes into departments of the
    Federal Government to expose corruption, inefficiency or waste”);
    
    McGrain, 273 U.S. at 179
    –80 (observing that it is not “a valid objection
    to the investigation that it might possibly disclose crime or wrongdoing on
    [the Attorney General’s] part”). Should the Foreign Affairs Committee, or
    another committee, articulate a legitimate oversight purpose for a future
    information request, the Executive Branch would assess that request as
    part of the constitutionally required accommodation process. But the
    Executive Branch was not confronted with that situation. The committee
    48
    House Committees’ Authority to Investigate for Impeachment
    chairmen unequivocally attempted to conduct an impeachment inquiry
    into the President’s actions, without the House, which has the “sole Power
    of Impeachment,” having authorized such an investigation. Absent such
    an authorization, the committee chairs’ passing mention of “oversight and
    legislative jurisdiction” did not cure that fundamental defect.
    C.
    We next address whether the House ratified any of the previous com-
    mittee subpoenas when it adopted Resolution 660 on October 31, 2019—
    after weeks of objections from the Executive Branch and many members
    of Congress to the committees’ efforts to conduct an unauthorized im-
    peachment inquiry. Resolution 660 provides that six committees of the
    House “are directed to continue their ongoing investigations as part of the
    existing House of Representatives inquiry into whether sufficient grounds
    exist for the House of Representatives to exercise its Constitutional power
    to impeach Donald John Trump, President of the United States of Ameri-
    ca.” Resolution 660, § 1. The resolution further prescribes certain proce-
    dures by which HPSCI and the Judiciary Committee may conduct hear-
    ings in connection with the investigation defined by that resolution.
    Resolution 660 does not speak at all to the committees’ past actions or
    seek to ratify any subpoena previously issued by the House committees.
    See Trump v. Mazars USA, LLP, 
    941 F.3d 1180
    , 1182 (D.C. Cir. 2019)
    (Rao, J., dissenting from the denial of rehearing en banc); see also Exclu-
    sion of Agency Counsel from Congressional Depositions in the Impeach-
    ment Context, 43 Op. O.L.C. __, at *5 (Nov. 1, 2019). The resolution
    “direct[s]” HPSCI and other committees to “continue” their investiga-
    tions, and the Rules Committee apparently assumed, incorrectly in our
    view, that earlier subpoenas were legally valid. See H.R. Rep. No. 116-
    266, at 3 (“All subpoenas to the Executive Branch remain in full force.”).
    But the resolution’s operative language does not address any previously
    issued subpoenas or provide the imprimatur of the House to give those
    subpoenas legal force.
    And the House knows how to ratify existing subpoenas when it chooses
    to do so. 37 On July 24, 2019, the House adopted a resolution that express-
    37 Even if the House had sought to ratify a previously issued subpoena, it could give
    that subpoena only prospective effect. As discussed above, the Supreme Court has
    recognized that the House may not cite a witness for contempt for failure to comply with
    49
    Opinions of the Office of Legal Counsel in Volume 44
    ly “ratif [ied] and affirm[ed] all current and future investigations, as well
    as all subpoenas previously issued or to be issued in the future,” related to
    certain enumerated subjects within the jurisdiction of standing or select
    committees of the House “as established by the Constitution of the United
    States and rules X and XI of the Rules of the House of Representatives.”
    H.R. Res. 507, 116th Cong. § 1 (2019) (emphasis added). There, as here,
    the House acted in response to questions regarding “the validity of . . .
    [committee] investigations and subpoenas.” 
    Id. pmbl. Despite
    that recent
    model, Resolution 660 contains no comparable language seeking to ratify
    previously issued subpoenas. The resolution directs certain committees to
    “continue” investigations, and it specifies procedures to govern future
    hearings, but nothing in the resolution looks backward to actions previ-
    ously taken. Accordingly, Resolution 660 did not ratify or otherwise
    authorize the impeachment-related subpoenas issued before October 31,
    which therefore still had no compulsory effect on their recipients.
    IV.
    Finally, we address some of the consequences that followed from our
    conclusion that the committees’ pre-October 31 impeachment-related
    subpoenas were unauthorized. First, because the subpoenas exceeded the
    committees’ investigative authority and lacked compulsory effect, the
    committees were mistaken in contending that the recipients’ “failure or
    refusal to comply with the subpoena [would] constitute evidence of ob-
    struction of the House’s impeachment inquiry.” Three Chairmen’s Letter,
    supra note 2, at 1. 38 As explained at length above, when the subpoenas
    were issued, there was no valid impeachment inquiry. To the extent that
    the committees’ subpoenas sought information in support of an unauthor-
    ized impeachment inquiry, the failure to comply with those subpoenas
    was no more punishable than were the failures of the witnesses in Wat-
    kins, Rumely, Kilbourn, and Lamont to answer questions that were beyond
    a subpoena unsupported by a valid delegation of authority at the time it was issued. See
    
    Rumely, 345 U.S. at 48
    ; see also 
    Exxon, 589 F.2d at 592
    (“To issue a valid subpoena, . . .
    a committee or subcommittee must conform strictly to the resolution establishing its
    investigatory powers[.]”).
    38 The letters accompanying other subpoenas, see supra note 9, contained similar
    threats that the recipients’ “failure or refusal to comply with the subpoena, including at
    the direction or behest of the President,” would constitute “evidence of obstruction of the
    House’s impeachment inquiry.”
    50
    House Committees’ Authority to Investigate for Impeachment
    the scope of those committees’ authorized jurisdiction. See 
    Watkins, 354 U.S. at 206
    , 215 (holding that conviction for contempt of Congress was
    invalid because, when the witness failed to answer questions, the House
    had not used sufficient “care . . . in authorizing the use of compulsory
    process” and the committee had not shown that the information was
    pertinent to a subject within “the mission[] delegated to” it by the House);
    
    Rumely, 345 U.S. at 42
    –43, 48 (affirming reversal of conviction for con-
    tempt of Congress because it was not clear at the time of questioning that
    “the committee was authorized to exact the information which the witness
    withheld”); 
    Kilbourn, 103 U.S. at 196
    (sustaining action brought by
    witness for false imprisonment because the committee “had no lawful
    authority to require Kilbourn to testify as a witness beyond what he vol-
    untarily chose to tell”); 
    Lamont, 18 F.R.D. at 37
    (dismissing indictment
    for contempt of Congress in part because the indictment did not suffi-
    ciently allege, among other things, “that the [Permanent Subcommittee on
    Investigations] . . . was duly empowered by either House of Congress to
    conduct the particular inquiry” or “that the inquiry was within the scope
    of the authority granted to the [sub]committee”). That alone suffices to
    prevent noncompliance with the subpoenas from constituting “obstruction
    of the House’s impeachment inquiry.”
    Second, we note that whether or not the impeachment inquiry was au-
    thorized, there were other, independent grounds to support directions by
    the Executive Branch that witnesses not appear in response to the commit-
    tees’ subpoenas. We recently advised you that executive privilege contin-
    ues to be available during an impeachment investigation. See Exclusion of
    Agency Counsel from Congressional Depositions in the Impeachment
    Context, 43 Op. O.L.C. __, at *2–5. The mere existence of an impeach-
    ment investigation does not eliminate the President’s need for confidenti-
    ality in connection with the performance of his duties. Just as in the
    context of a criminal trial, a dispute over a request for privileged infor-
    mation in an impeachment investigation must be resolved in a manner that
    “preserves the essential functions of each branch.” United States v. Nixon,
    
    418 U.S. 683
    , 707 (1974). Thus, while a committee “may be able to
    establish an interest justifying its requests for information, the Executive
    Branch also has legitimate interests in confidentiality, and the resolution
    of these competing interests requires a careful balancing of each branch’s
    need in the context of the particular information sought.” Exclusion of
    Agency Counsel from Congressional Depositions in the Impeachment
    Context, 43 Op. O.L.C. __, at *4.
    51
    Opinions of the Office of Legal Counsel in Volume 44
    Accordingly, we recognized, in connection with HPSCI’s impeachment
    investigation after October 31, that the committee may not compel an
    executive branch witness to appear for a deposition without the assistance
    of agency counsel, when that counsel is necessary to assist the witness in
    ensuring the appropriate protection of privileged information during the
    deposition. See 
    id. at *4–5.
    In addition, we have concluded that the testi-
    monial immunity of the President’s senior advisers “applies in an im-
    peachment inquiry just as it applies in a legislative oversight inquiry.”
    Letter for Pat A. Cipollone, Counsel to the President, from Steven A.
    Engel, Assistant Attorney General, Office of Legal Counsel at 2 (Nov. 3,
    2019).
    Thus, even when the House takes the steps necessary to authorize a
    committee to investigate impeachment and compel the production of
    needed information, the Executive Branch continues to have legitimate
    interests to protect. The Constitution does not oblige either branch of
    government to surrender its legitimate prerogatives, but expects that each
    branch will negotiate in good faith with mutual respect for the needs of
    the other branch. See United States v. Am. Tel. & Tel. Co., 
    567 F.2d 121
    ,
    127 (D.C. Cir. 1977) (“[E]ach branch should take cognizance of an im-
    plicit constitutional mandate to seek optimal accommodation through a
    realistic evaluation of the needs of the conflicting branches in the particu-
    lar fact situation.”); see also Memorandum for the Heads of Executive
    Departments and Agencies from President Ronald Reagan, Re: Proce-
    dures Governing Responses to Congressional Requests for Information
    (Nov. 4, 1982). The two branches should work to identify arrangements in
    the context of the particular requests of an investigating committee that
    accommodate both the committee’s needs and the Executive Branch’s
    interests.
    For these reasons, the House cannot plausibly claim that any executive
    branch official engaged in “obstruction” by failing to comply with com-
    mittee subpoenas, or directing subordinates not to comply, in order to
    protect the Executive Branch’s legitimate interests in confidentiality and
    the separation of powers. We explained thirty-five years ago that “the
    Constitution does not permit Congress to make it a crime for an official to
    assist the President in asserting a constitutional privilege that is an inte-
    gral part of the President’s responsibilities under the Constitution.” Pros-
    ecution for Contempt of Congress of an Executive Branch Official Who
    Has Asserted a Claim of Executive Privilege, 
    8 Op. O.L.C. 101
    , 140
    (1984). Nor may Congress “utilize its inherent ‘civil’ contempt powers to
    52
    House Committees’ Authority to Investigate for Impeachment
    arrest, bring to trial, and punish an executive official who assert[s] a
    Presidential claim of executive privilege.” 
    Id. at 14
    0 n.42. We have re-
    affirmed those fundamental conclusions in each of the subsequent dec-
    ades. 39
    The constitutionally required accommodation process, of course, is a
    two-way street. In connection with this investigation, the House commit-
    tees took the unprecedented steps of investigating the impeachment of a
    President without any authorization from the full House; without the
    procedural protections provided to Presidents Nixon and Clinton, see
    supra note 12; and with express threats of obstruction charges and uncon-
    stitutional demands that officials appear and provide closed-door testimo-
    ny about privileged matters without the assistance of executive branch
    counsel. Absent any effort by the House committees to accommodate the
    Executive Branch’s legitimate concerns with the unprecedented nature of
    the committees’ actions, it was reasonable for executive branch officials
    to decline to comply with the subpoenas addressed to them.
    V.
    For the reasons set forth above, we conclude that the House must ex-
    pressly authorize a committee to conduct an impeachment investigation
    and to use compulsory process in that investigation before the committee
    39 See, e.g., Attempted Exclusion of Agency Counsel from Congressional Depositions of
    Agency Employees, 43 Op. O.L.C. __, at *14 (May 23, 2019) (“[I]t would be unconstitu-
    tional to enforce a subpoena against an agency employee who declined to appear before
    Congress, at the agency’s direction, because the committee would not permit an agency
    representative to accompany him.”); Testimonial Immunity Before Congress of the
    Former Counsel to the President, 43 Op. O.L.C. __, at *20 (May 20, 2019) (“The consti-
    tutional separation of powers bars Congress from exercising its inherent contempt power
    in the face of a presidential assertion of executive privilege.”); Whether the Department of
    Justice May Prosecute White House Officials for Contempt of Congress, 
    32 Op. O.L.C. 65
    , 65–69 (2008) (concluding that the Department cannot take “prosecutorial action, with
    respect to current or former White House officials who . . . declined to appear to testify, in
    response to subpoenas from a congressional committee, based on the President’s assertion
    of executive privilege”); Application of 28 U.S.C. § 458 to Presidential Appointments of
    Federal Judges, 
    19 Op. O.L.C. 350
    , 356 (1995) (“[T]he criminal contempt of Congress
    statute does not apply to the President or presidential subordinates who assert executive
    privilege.”); see also Authority of Agency Officials to Prohibit Employees from Providing
    Information to Congress, 
    28 Op. O.L.C. 79
    , 80–82 (2004) (explaining that the Executive
    Branch has the constitutional authority to supervise its employees’ disclosure of privi-
    leged and other information to Congress).
    53
    Opinions of the Office of Legal Counsel in Volume 44
    may compel the production of documents or testimony in support of the
    House’s “sole Power of Impeachment.” U.S. Const. art. I, § 2, cl. 5. The
    House had not authorized such an investigation in connection with the
    impeachment-related subpoenas issued before October 31, 2019, and the
    subpoenas therefore had no compulsory effect. The House’s adoption of
    Resolution 660 did not alter the legal status of those subpoenas, because
    the resolution did not ratify them or otherwise address their terms.
    STEVEN A. ENGEL
    Assistant Attorney General
    Office of Legal Counsel
    54