I suppose it's because uneducated Christian conservatives will vote for the more conservative candidate no matter what, and this group constitutes a large percentage of the electorate.
Get your nose out of the air.
Yeah, I'd characterize these people more as willfully ignorant rather than uneducated. :-) Seriously though, both parties have their share of this type of people. South Memphis, for instance, is probably 95%+ Democratic (super-Christian as well) and I don't think too many voters there are terribly informed. It's just the nature of democracy.