and I am still not convinced that the social issues would implode under Rudy. until we hear what he has to say about judges, his pro-choice position as mayor of a city with a 9:1 Democratic registration doesn't tell us anything. gay civil union is going to be an issue left to the states - that's the status quo today.
States vote to ratify Amendments.
It was landmark U.S. Supreme Court precedent Reynolds v. United States in 1878 that made separation of church and state a dubiously legitimate point of case law, but more importantly; it confirmed the Constitutionality in statutory regulation of marriage practices.
The U.S. Constitution says this:
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;...