Short answer: he doesn't. It's a 2004 election issue only.
The long answer: there's a strange way it could happen.
To get an amendment passed and ratified requires these steps:
- Pass both the U.S. House of Representatives and the U.S. Senate by two thirds supermajorities, the same as a veto override.
- Pass the state legislatures in three quarters of the states (i.e. 38 states).
Option #1 seems awfully difficult. One would think there are enough Democrats with spine (please?) and thoughtful Republicans to block the amendment in both houses.
Option #2 seems slightly easier, but it should be moot.
There's another path that an amendment can follow. That's a Constitutional Convention. Two thirds of the states can call it, then the convention proposes amendments which then must be ratified by 38 states. It is possible for state conventions, rather than state legislatures, to do the ratifying.
This path has never been used. But it is a (remote) possibility, and the Christian Right could conceivably persuade 34 state legislatures to convene a constitutional convention.
I make this point because it reinforces how important it is for Democrats-with-spine (i.e. reformers) to win up and down the ticket this November. State representatives and senators count, and many have more direct impact on Americans' daily lives than politicians in Washington.