Not the only veto she issued tonight, either. She also rejected a bill that would have allowed people to carry guns on state college campuses on grounds that it was “poorly written.” Not a total surprise given the political climate in the state after Gabby Giffords’s shooting, but a mild surprise given the grassroots conservative cred Brewer built for herself by championing Arizona’s immigration law.

This one’s a genuine surprise, though.

Arizona Gov. Jan Brewer on Monday vetoed a bill to require President Barack Obama and other presidential candidates to prove their U.S. citizenship before their names can appear on the state’s ballot…

“I do not support designating one person [i.e. the secretary of state] as the gatekeeper to the ballot for a candidate, which could lead to arbitrary or politically motivated decisions,” said Brewer, who was secretary of state until she became governor in 2009.

“In addition, I never imagined being presented with a bill that could require candidates for president of the greatest and most powerful nation on Earth to submit their ‘early baptismal circumcision certificates’ among other records to the Arizona secretary of state,” she said. “This is a bridge too far.”

I’m guessing there’s some local political angle that explains this, but I can’t figure out what it is and some furious googling reveals nothing. Any Arizonans willing and able to explain? She just started her new term so electoral politics is immaterial. Is there some core agenda item that she needs Democratic help to pass? Or is she trying to build goodwill with Obama for better cooperation on immigration? Or, just maybe, did she genuinely believe that the bill was stupid and embarrassing to Arizona? All theories welcome.