Article V of the Constitution outlines how to amend (modify) the document. It consists of two steps: proposal and ratification.
1. Propose An Amendment
Either Congress or the States can propose an amendment ot the Constitution.
- Both Houses of Congress must propose the amendment with a two-thirds vote. This is how all current amendments have been offered.
- Two-thirds of the State legislatures must call on Congress to hold a Constitutional Convention.
2. Ratify An Admendment
Regardless of how the amendment is proposed, it must be ratified by the States.
- Three-fourths of the State legislatures must approve of the amendment proposed by Congress, or
- Three-fourths of the states must approve the amendment via ratifying conventions. This method has only been used once, to repeal Prohibition (21st Amendment).
Is there a timeline for ratification? The US Supreme Court has held that ratification must happen within "some reasonable time after the proposal." Since the 18th Amendment, Congress has set a term of seven years for ratification.
Only 33 amendments have received a two-thirds vote from both Houses of Congress. Of those, only 27 have been ratified by the States. Perhaps the most visible failure is the Equal Rights Amendment.
Article V
- 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.