Don't forget Methodists. They're pretty liberal too.
The Methodist church I went to in high school actually had Harry Blackmun as a guest speaker.
I can't tell you how many conservative Christians tried to get me to read "The Purpose Driven Life". I didn't read it, didn't care to, and knew that I made the right choice not to when I saw the fat-faced pastor who wrote it say the prayer at Obama's inauguration.
I trust libertarians 100 times over someone who classifies themself as "Christian" to vote for the true constitutionalist in a given race.
The true constitutionalist will always be a moral individual who will support the principles of “social conservatism.” It can be no other way because the Declaration of Independence and the Constitution are based on Natural Law.