They say statistics can be used to prove anything, so I'm not expecting this to change your mind, but poll after poll shows that the majority of people in the USA are Christians.

http://www.adherents.com/rel_USA.html

But there are two things: (1) relevance and (2) I'm guessing the consensus among Americans is that we wouldn't want merely a majority-rule democracy, but a democracy that also respects the rights of minorities.

Using the reasoning of popularity, we could put "Land of the Whites" on our money.