Why is religion such a big part this time??

My Way News - Kerrey Apologizes to Obama Over Remark

Okay so why is religion playing such a huge part in this rounds presidential elections...okay I can kind of, slightly see where some people--some very paranoid people--would be worried about getting a muslim in office.

But why is this round so charged?

This is not the first I've heard of Obama being called a muslim...in fact just ran into it on Yahoo Questions this morning....I couldn't believe that someone didn't check this out. This guy was muslim and was pushing for fellow muslims to register just to vote for Obama so we would have the first muslim president.
Not a single person seem to be correcting him at the time.
Not that it matters....what got me was the fact that he didn't bother to do any checking himself...he took it as scripture because it came from the head of his synagogue.