The Republican Party is not going to nominate someone who is even "mildly" pro-choice, unless that person opposes abortion except in cases of rape and incest. That is, by George W. Bush's lights, a pro-life position.
That's why I think that John McCain is going to show signs of life in the primary direction after the 2006 elections. McCain would still like to be president, and, unless Cheney quits and Bush nominates Rice to fill the VP spot, he'd have a great shot in 2008.
Watch McCain start courting the Christian right early next year.
Take this for what its worth who sent McCain real money at one point.