I apologize for my lack of common sense here but, isn't it already law that Presidents must be natural born citizens? So what's the problem with a requirement to prove you're a POTUS candidate abiding by the law? I will tell you straight up, I don't buy into this birther bullsh**t, and believe the President was born in Hawaii. However, since when is it against some higher moral code when voting for a bill that enforces law? If I missed something in this bill I should have read let me know so I can recuse my statement and reform my opinion.
It's not really about the birth certificate. Aside from the lunatic fringe who really believes in the conspiracy theory (and as I've said before, you could invent a time machine, go back in time and record Obama's birth, and it would still not be enough for them), it's a way to cast doubt on the legitimacy of Obama's Presidency; saying he wasn't born here is just a way of saying that he's The Other, he's not one of "us".