Just maybe people don't want to see trash like Kerry and his wife running this country.
Bush won in spite of the Christian zealots in the party - not because of them. If they would leave the party and form their own, they would be replaced by a voting block twice their number who have subscribe to conservative ideals but detest the "morality police" aspect of the party.
I am not saying that Christians should leave the party as I have no doubt that most of these zealots are in Christians in name only. They only embrace religion so they can have a rule book to thump those who don't subscribe to the same rule book over the head with it. We have examples in this thread - somehow Kid Rock is "scum".
95% of the Christians are live their own lives and let others live their's. Its the small, vocal minority that scare everyone else off.