[lostalex]

Well, in a democratic republic you are electing someone to represent your views in the government. If your views are christian then obviously you'd be more inclined to vote for a christian. Obviously the US is a majority christian country, and that probably won't be changing anytime soon, as the population is becoming more and more Latino, and Latinos tend to be very conservative catholic.

There have been some presidents that were probably atheist or agnostic, like Jefferson and Lincoln, but they still obviously needed to convince people they would represent a christian view point for them while in office and assure them that christian values would not be discriminated against and so would pander to christians a bit.