This mechanism is used to propose constitutional amendments

The Congress, whenever two thirds of both Houses shall deem it necessary, shall propose Amendments to this Constitution, or, on the Application of the Legislatures of two thirds of the several States, shall call a Convention for proposing Amendments, which, in either Case, shall be valid to all Intents and Purposes, as Part of this Constitution, when ratified by the Legislatures of three fourths of the several States, or by Conventions in three fourths thereof, as the one or the other Mode of Ratification may be proposed by the Congress; Provided that no Amendment which may be made prior to the Year One thousand eight hundred and eight shall in any Manner affect the first and fourth Clauses in the Ninth Section of the first Article; and that no State, without its Consent, shall be deprived of its equal Suffrage in the Senate.

The first method for proposing amendments permits two-thirds of the Members of the House and Senate to propose a constitutional amendment when they “shall deem it necessary.” 1 Footnote
U.S. Const. art. V . This is the only method that has thus far been used to propose amendments to the Constitution.

The Supreme Court addressed Article V’s procedures for congressionally proposed constitutional amendments in the National Prohibition Cases , which challenged the validity of the Eighteenth Amendment.2 Footnote
253 U.S. 350 (1920) . In these cases, the Supreme Court held that both the House and Senate must propose a constitutional amendment by a vote of two-thirds of the Members present (rather than two-thirds of the entire membership present and absent), assuming the presence of a quorum.3 Footnote
Id. at 386 ( “The two-thirds vote in each house which is required in proposing an amendment is a vote of two-thirds of the members present—assuming the presence of a quorum and not a vote of two-thirds of the entire membership, present and absent.” ). The Court also held that Congress’s successful proposal of an amendment indicates that Congress considers the amendment “necessary.” 4 Footnote
Id. Thus, it appears that the Court will not require Congress to state that an amendment is necessary specifically or second-guess Congress’s judgment on the issue of necessity.5 Footnote
See id.

Although Members of Congress have introduced more than 11,000 proposed amendments to the Constitution since the Founding,6 Footnote
U.S. Senate: Measures Proposed to Amend the Constitution , https://www.senate.gov/legislative/MeasuresProposedToAmendTheConstitution.htm. Congress has approved only thirty-three proposed amendments by the requisite two-thirds vote.7 Footnote
For a list of constitutional amendments that Congress proposed but the states did not ratify, see Intro.3.7 Proposed Amendments Not Ratified by the States. Congress has historically proposed constitutional amendments by enacting a joint resolution.8 Footnote
1 Annals of Cong. 735 (1789) . Following historical practice involving proposing amendments, which included the Bill of Rights, Members of Congress have proposed amendments as codicils (i.e., supplementary articles), rather than line-by-line revisions to the Constitution’s text.9 Footnote
Id. at 733–44 (1789) . After congressional approval, proposed amendments are sent to the states for potential ratification.10 Footnote
Under current federal law, the Archivist of the United States is responsible for certifying a state’s ratification of a constitutional amendment. See National Archives and Records Administration Act of 1984, 98 Stat. 2291 (codified at 1 U.S.C. § 106b ).

Footnotes 1 U.S. Const. art. V . 2 253 U.S. 350 (1920) . 3 Id. at 386 ( “The two-thirds vote in each house which is required in proposing an amendment is a vote of two-thirds of the members present—assuming the presence of a quorum and not a vote of two-thirds of the entire membership, present and absent.” ). 4 Id. 5 See id. 6 U.S. Senate: Measures Proposed to Amend the Constitution , https://www.senate.gov/legislative/MeasuresProposedToAmendTheConstitution.htm. 7 For a list of constitutional amendments that Congress proposed but the states did not ratify, see Intro.3.7 Proposed Amendments Not Ratified by the States. 8 1 Annals of Cong. 735 (1789) . 9 Id. at 733–44 (1789) . 10 Under current federal law, the Archivist of the United States is responsible for certifying a state’s ratification of a constitutional amendment. See National Archives and Records Administration Act of 1984, 98 Stat. 2291 (codified at 1 U.S.C. § 106b ).