Gov. Jan Brewer (R) veteos bill that requires POTUS candidates to prove US birth

[Cincinnatus]

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.