Does the US require a House vote to begin an impeachment inquiry?
News sources such as this CNN article seem to show a disagreement between the White House saying that a House vote is required, while the Speaker of the House holds that they have the power to declare one on their own.
Does the US require a House vote to begin an impeachment inquiry?
Some answers look at whether there is a historical precedent. That is irrelevant. The question is what is required and what is not. There is no current requirement that a resolution be voted on by the House in order to initiate a formal, official impeachment inquiry.
If a president were caught by eye-witnesses and on video performing blood sacrifices of infants in the Lincoln Bedroom, surely it would be unprecedented to remove a President from office for those actions. The fact that it was unprecedented would really have no bearing on whether such actions should proceed or whether they were authorized.
The Constitution doesn’t offer specific guidance on rules for impeachment inquiries and the House determines its own rules of parliamentary conduct. According to the CRS (Congressional Research Service), the House’s rules allow for an impeachment inquiry to go forward without an initial resolution but the matter would move on the Judiciary Committee at some point.
As pointed out in a since-deleted answer, part of why, historically, the process of an authorizing resolution was followed, in part, was because that authorizing resolution would create the authorization for subpoena and other investigative powers. Those powers now exist with the House majority on a permanent basis. One of the main reasons why the precedent was to go via resolution no longer exists.
In addition, Pelosi doesn't need the House vote authorizing an inquiry because her caucus already has extra legal authority compared to past inquiries.
During the Clinton and Nixon impeachment inquiries, the House passed their inquiry resolutions so they could gain tools like more subpoena power and depositions, and included in those resolutions were nods to bipartisanship that gave the minority party subpoena power, too.
But the House rules have changed since the last impeachment of a president more than two decades ago. In this Congress, the House majority already has unilateral subpoena power, a rule change that was made when Republicans last controlled the House, so Democrats don't need to pass any resolution to grant those powers.
Each committee may conduct at any time such investigations and studies as it considers necessary or appropriate in the exercise of its responsibilities under rule X.
(Rule XI(1)(b)(1), page 16)
In turn, Rule X includes in the judiciary committee's responsibilities matters relating to "Subversive activities affecting the internal security of the United States" (Rule X(1)(l)(19)).
The constitution provides in Article I, section 5, that "Each House may determine the Rules of its Proceedings...," so really the only entity that can require the House of Representatives to pass a resolution before embarking on an impeachment inquiry is the House of Representatives itself.
As noted in a comment, this extends to the remedy if it were found that the inquiry actually was in violation of the house rules: in that case, the only remedy lies with the house itself. The courts cannot intervene.
Does the US require a House vote to begin an impeachment inquiry?
This document from the United States House of Representatives (History web page) indicates that a vote is required.
The House's Role
The House brings impeachment charges against federal officials as part of its oversight and investigatory responsibilities. Individual Members of the House can introduce impeachment resolutions like ordinary bills, or the House could initiate proceedings by passing a resolution authorizing an inquiry. The Committee on the Judiciary ordinarily has jurisdiction over impeachments, but special committees investigated charges before the Judiciary Committee was created in 1813. The committee then chooses whether to pursue articles of impeachment against the accused official and report them to the full House.
A resolution requires a vote. (The "hopper" method, by a member, does not have an inquiry.)
A referenced document from the above is,
§ 6. In General; Initiation and Referral of Charges
Under the modern practice, an impeachment is normally instituted by the House by the adoption of a resolution calling for a committee investigation of charges against the officer in question. This committee may, after investigation, recommend the dismissal of charges or it may recommend impeachment.
Initiation of Charges
In most cases, impeachment proceedings in the House have been initiated either by introducing a resolution of impeachment through the hopper or by offering a resolution of impeachment on the floor as a question of the privileges of the House.
Referral to Committee
Resolutions introduced through the hopper that directly call for an impeachment are referred to the Committee on the Judiciary, whereas resolutions merely calling for a committee investigation with a view toward impeachment are referred to the Committee on Rules.
§ 7. Committee Investigations
Committee impeachment investigations are governed by those portions of Rule XI relating to committee investigative and hearing procedures, and by any rules and special procedures adopted by the House and by the committee for the inquiry. ... The House may by resolution waive or supplement a requirement of these rules in a particular case. In several recent instances, the House agreed to a resolution authorizing the counsel to the Committee on the Judiciary to take depositions of witnesses in an impeachment investigation and waiving the provision of Rule XI that requires at least two committee members to be present during the taking of such testimony.
An investigative subcommittee charged with an impeachment inquiry is limited to the powers expressly authorized by the House or by the full committee.
Again resolution (or it's implication) appears often in this document.
It appears, to me, that whatever Speaker Pelosi is doing, with regard to the impeachment inquiry, is unprecedented.
Any clause referring to rule X is strictly legislative by rule X 2.
Rule XI 2(m)(1) (shown below) is a general power to investigate, including the power to issue subpoenas. The matters that may be investigated are those in rule X (strictly legislative) or those under clause 2 of rule XII (shown below). Rule XII 2(a) and (b) are strictly legislative, (c) gives the Speaker authority to refer matters (legislative or otherwise) to one or more committees, and (d) does not apply. (A bill, resolution, or other matter mentioned in 2(a) applies throughout rule XII 2.) But, note that rule XII 2(b) mentions Precedents, rulings, or procedures in effect before the Ninety-Fourth Congress, which may apply to impeachment. (The Ninety-fourth Congress was 1975-1976 when rule XI 2(m) was put into effect.)
The word "matter(s)" occurs 140 times in the House Rules. The word "impeachment" is not mentioned. An impeachment inquiry is not a legislative matter. It is a quasi-judicial proceeding.
A narrow reading of rule XII 2 implies that, in the absence of a resolution, the House has no authority to conduct an impeachment proceeding of any type.
A broad reading of rule XII 2 implies that the unmentioned "impeachment" is simply an "other matter" to be referred in a manner chosen by the Speaker and without any votes or rules for the conduct of an impeachment inquiry. By implication, any investigation undertaken by any committee involving a "civil officer" is potentially an impeachment inquiry. Application of this reading is unprecedented.
RULE XI - PROCEDURES OF COMMITTEES AND UNFINISHED BUSINESS
Power to sit and act; subpoena power
(1) For 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), a committee or subcommittee is authorized (subject to subparagraph (3)(A))—
(A) to sit and act at such times and places within the United States, whether the House is in session, has recessed, or has adjourned, and to hold such hearings as it considers necessary; and
(B) to require, by subpoena or otherwise, the attendance and testimony of such witnesses and the production of such books, records, correspondence, memoranda, papers, and documents as it considers necessary.
(2) The chair of the committee, or a member designated by the chair, may administer oaths to witnesses.
(i) Except as provided in subdivision (A)(ii), a subpoena may be authorized and issued by a committee or subcommittee under subparagraph (1)(B) in the conduct of an investigation or series of investigations or activities only when authorized by the committee or subcommittee, a majority being present. The power to authorize and issue subpoenas under subparagraph (1)(B) may be delegated to the chair of the committee under such rules and under such limitations as the committee may prescribe. Authorized subpoenas shall be signed by the chair of the committee or by a member designated by the committee.
(ii) In the case of a subcommittee of the Committee on Ethics, a subpoena may be authorized and issued only by an affirmative vote of a majority of its members.
(B) A subpoena duces tecum may specify terms of return other than at a meeting or hearing of the committee or subcommittee authorizing the subpoena.
(C) Compliance with a subpoena issued by a committee or subcommittee under subparagraph (1)(B) may be enforced only as authorized or directed by the House.
RULE XII - RECEIPT AND REFERRAL OF MEASURES AND MATTERS
(a) The 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 in accordance with the provisions of this clause.
(b) The Speaker shall refer matters under paragraph (a) in such manner as to ensure to the maximum extent feasible that each committee that has jurisdiction under clause 1 of rule X over the subject matter of a provision thereof may consider such provision and report to the House thereon. Precedents, rulings, or procedures in effect before the Ninety-Fourth Congress shall be applied to referrals under this clause only to the extent that they will contribute to the achievement of the objectives of this clause.
(c) In carrying out paragraphs (a) and (b) with respect to the referral of a matter, the Speaker—
(1) shall designate a committee of primary jurisdiction (except where the Speaker determines that extraordinary circumstances justify review by more than one committee as though primary);
(2) may refer the matter to one or more additional committees for consideration in sequence, either initially or after the matter has been reported by the committee of primary jurisdiction;
(3) may refer portions of the matter reflecting different subjects and jurisdictions to one or more additional committees;
(4) may refer the matter to a special, ad hoc committee appointed by the Speaker with the approval of the House, and including members of the committees of jurisdiction, for the specific purpose of considering that matter and reporting to the House thereon;
(5) may subject a referral to appropriate time limitations; and
(6) may make such other provision as may be considered appropriate.
(d) A bill for the payment or adjudication of a private claim against the Government may not be referred to a committee other than the Committee on Foreign Affairs or the Committee on the Judiciary, except by unanimous consent.
According to Wikipedia, the procedure is threefold. First, there are investigations by congressional committees. Second, the House of Representatives draws up articles of impeachment and votes on them. When these votes are passed then the defendant is impeached. Third, the Senate holds a trial. If two-thirds of the Senate votes to convict on (one of) the articles of impeachment then the defendant is removed from office.
The NYT also has an article on this, regarding the process it draws from historical examples. It writes:
In both the Nixon and the Clinton cases, the House Judiciary Committee first held an investigation and recommended articles of impeachment to the full House. In theory, however, the House of Representatives could instead set up a special panel to handle the proceedings — or just hold a floor vote on such articles without any committee vetting them.
When the full House votes on articles of impeachment, if at least one gets a majority vote, the president is impeached — which is essentially the equivalent of being indicted.
So it's normal for a presidential impeachment to be preceded by an inquiry in which congressional committees investigate by hearing witnesses.
One may compare it to a police investigation before the district attorney (DA) brings charges to the courtroom. In high profile cases, the DA's office may have multiple people considering whether to take it to trial. Taking it to trial means filing an indictment and that's similar to the House bringing charges in the form of articles of impeachment. Then, a trial takes place at the end of which a jury determines if the defendant is guilty of (some of) the charges, which is similar to the Senate's role in the impeachment process.
While the constitution doesn't specify the first step of the impeachment process as explained in my answer explicitly. The start of these investigations are said to be the start of the impeachment process but do not require a specific vote. Establishing a dedicated committee to investigate a president may require a vote.
The difficulty in answering your question with a solid yes or no lies with the ill-defined start of the impeachment inquiry. When there's a vote at the beginning of the inquiry saying that the inquiry starts then it's a clear cut case. When there's no vote, then it's less clear but it doesn't mean there can't be an inquiry without a vote.