Welcome to the United States.
Fundamentalists, and foreign fundamentalists especially, ought not to determine who our candidates can be. Citizens of the United States run for public office and vote for their choice of candidate at our own pleasure.
I'm a heretic too. A Catholic one. I still get to participate in public life. Obama is at greater risk than I because the Inquisition is no longer burning people.
For his courage to run, he should have our admiration. He should be able to count on us to vote for or against him based on what he proposes to do in office rather than any speculation about fundamentalist ire or fear at his personal religious convictions or his religious past. That goes for fundamentalism of any type.