Mayor Bloomberg's endorsement is a big deal, because, well, he's mayor of New York City, he's a billionaire,and he's a media baron. While he hasn't weighed in (at least not publicly) about the presidential election, Bloomberg is stepping in to throw his support behind Republican Senator Scott Brown from Massachusetts by holding a fundraiser for Brown at his Upper East Side townhouse on August 15. Does Bloomberg like Brown because Brown's opponent, Elizabeth Warren, is critical of Wall Street, would want to end tax breaks for the wealthiest Americans, and thinks Brown would help weaken Wall Street reform? No—the mayor's office says it's because of Brown's stance on guns, Bloomberg's current big issue.

Mayoral spokesperson Stu Loeser said, "The Mayor supports independent, centrist legislators who buck party orthodoxies and build bridges across the aisle that help New York City. Senator Brown was the key Senator who stood up to stop the NRA’s bill for concealed-carry reciprocity when it was headed to the Senate. This bill, which is the NRA’s top priority, would let anyone with a permit from a state with weak gun laws like South Carolina or Kentucky carry a hidden weapon in New York City."

And spokesperson Marc LaVorgna further explained, "The Mayor has been fighting the NRA for years on this bill and they nearly made it a reality—until we helped cause them to lose a floor vote in the U.S. Senate in June 2009, the first time anyone I know can remember the NRA losing a floor vote in the Senate. It was known as the Thune Amendment at the time, after Sen. John Thune... The issue keeps coming up, as the NRA is determined to pass this bill. The U.S. House again passed a concealed carry bill in November 2011. The Senate continues to be our best chance to ensure this never passes. Senator Brown’s strong public opposition to the bill is part of the reason supporters have not been able to get it up again for a Senate vote (they are vote counting), and if they do, we know we have a Republican on our side."

Side note: The Mayor and Brown differ sharply on immigration reform. Bloomberg has spoken out in favor of amnesty for immigrants already here, while Brown totally opposes amnesty (Warren supports immigration reform and giving existing illegal immigrant a path to citizenship).