Considering the requirements to be president of the United States are pretty minimal and three of the four are spelled out in the United States constitution.  Here the are (and if I make a mistake, I'm doing this from memory) -

1.  The President must be at least 35 years of age.
2. The President must be a natural born United States citizen.
3.  The President must have resided in the United States for at least (I think) ten years prior to election.
4.  He must be elected.  (This is the one that I don't think is explicitly stated.)