He's Christian though, but I can see how it's easy to get confused they're very similar religions

His middle name is Hussein. That's it. That's the most tangible "proof" they have, aside from the fact he's not white and that makes them anxious.

Not that having a Muslim president would be a problem in the first place. The people that assume he is and that it's something to freak out about are seriously fucked in the head.