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.

**Comment: Although a movement to call a constitutional convention to approve an amendment requiring a balanced federal budget gained temporary momentum in 1979, only the first method of proposing amendments has ever been applied successfully.

All proposals, except the one to repeal the 18th Amendment, have been referred to state legislatures. In that one instance, Congress prescribed that the proposal should be ratified by popularly elected conventions chosen especially for the purpose, but it left the details of their summoning to the several state legislatures. What resulted in most states was a popular referendum; the conventions were made up almost entirely of delegates previously pledged to vote for or against the proposed amendment.

During the controversy in the 1970s over ratification of the proposed Equal Rights Amendment (ERA), the perennial question arose as to whether a state legislature that has ratified an amendment may later reconsider its vote before the amendment is ratified by three-fourths of the state legislatures. This question has not been definitively settled. In passing a resolution in 1978 to extend the deadline for ratification of the amendment, however, the Senate specifically rejected an amendment to allow the states to rescind earlier ERA ratification.

The first of the two exceptions to the amending power became obsolete in 1808. The second, that "no State, without its Consent, shall be deprived of its equal Suffrage in the Senate," explains why the Senate is the only legislative body in the United States whose composition is exempt from the Supreme Court's one-man, one-vote ruling in Reynolds v. Sims (1964).**