What exactly is the "Christian vote"? According to the media, Christian vote includes the 77% of
voter-aged Americans who identify themselves as Christians:
52% are Protestants and 25% are Roman Catholics.
Since the Christian vote comprises the majority of voter-aged Americans, if it
were to vote as a bloc, it would in theory determine the outcome of every
political race, presidential or otherwise (note that the Protestant bloc's
52% on its own comprises an absolute majority of all American voters).