The support by Bloomberg was unexpected, with both the Obama and Romney campaigns seeking the Mayor's endorsement, given that he is in a position to influence independent voters around the country.

Bloomberg said if Obama listens to people on "both sides of the aisle, and builds the trust of moderates, he can fulfill the hope he inspired four years ago and lead our country toward a better future for my children and yours. And that's why I will be voting for him."

A lifelong democrat who had turned Republican before becoming an independent, Bloomberg said Romney is a "good and decent man" who as Massachusetts governor had taken important steps to tackle climate change, including signing on to a regional cap-and-trade plan.