Well, don't look for one who admits to be an atheist.
Amazingly, other polls have found that Americans were much more likely to vote for a Muslim (our current dreaded enemy) than for an atheist.
I think there are far more atheists in government than people are aware of. Barny Frank came out as homosexual and spent another twenty or thirty years in Congress. It wasn't until after he retired that he admitted to being an atheist.
The incredible stupidity of the American people seems to be increasing exponentially (although few of them know that that word means).