The billionaire three-term New York City mayor was the subject of nearly endless chatter about a third-party entrant into the race earlier this cycle. Though that speculation has subsided as the race progressed, Bloomberg is a big favorite of moderate-minded political insiders and is still talked about as having a future in American politics.

In many ways, he’s an ideal running mate: he’s incredibly wealthy, he has friends on both sides of the aisle and his positions on social issues — he’s pro-abortion rights, for example — would help Romney win over independent and moderate voters with whom he needs a crucial advantage in November.

Despite his appeal for moderate voters, though, picking Bloomberg would likely result in the same kind of conservative backlash McCain got when floating Democrat Joe Lieberman as a potential running mate. For Romney, who’s also had trouble winning the hearts of the party’s conservative voters, picking a socially liberal pol from New York who’s also very much in favor of stricter gun control would be exactly the kind of choice that wouldn’t sit well with the GOP base.