Unable to prevent Barack Obama from becoming president, rigid followers of the Constitution have turned their attention to another young, charismatic politician many think could one day occupy the White House. The birthers are calling for U.S. Sen Marco Rubio, the budding Republican star from Florida.

"It's nothing to do with him personally. But you can't change the rules because you like a certain person. Then you have no rules," said New Jersey lawyer Mario Apuzzo.

Their question is whether Rubio is a "natural born citizen." Here are some documents that might help answer that question.