While we do separate church and state (kind of) if a person runs for President who is atheist, I can guarantee that person will not be elected. The majority of the people in the United States hold some kind of religion or greater order hence; they want a leader who also reflects those principals.

Since this country was originally founded by the religiously persecuted it is unlikely that those words will ever be removed.
I don't measure a man's success by how high he climbs but how high he bounces when he hits bottom.
--General George S. Patton