Via New York Times:
[D]uring casual conversations at charity event a few days ago, Mr. Bloomberg was far chattier — and candid — about the [presidential election], according to three people who overheard him.
Mr. Bloomberg said that he believed Mr. Romney would probably be better at running the country than Mr. Obama, according to two guests.
But Mr. Bloomberg said he could not support Mr. Romney because he disagreed with him on so many social issues, these two people said. The mayor mentioned two such issues: abortion rights and gun control.