UPDATE: Colin Campbell gives Ezra Klein's take on Mayor Bloomberg's endorsement of Obama

From Colin Campbell's 11/1/12 "Evening Read: ‘I Don’t Mind Joining the Circus’"  ---  quoting the Washington Post's blogger Ezra Klein on Mr. Bloomberg’s endorsement:

“1. Bloomberg’s endorsement is one of the most fascinating and strategically designed endorsements I’ve seen.
2. By endorsing this close to the election, he’s trying to impose a real cost on the Republican Party for climate denialism.
3. By attacking Obama and praising the old Romney in his op-ed, he’s buttressing his role as an arbiter of the center.
4. And then he’s spending that credibility to make “acting to stop climate change” a centrist issue.
5. Bloomberg’s not endorsing Obama so much as he’s trying to reset the incentives on climate change. It’s a huge play.
6. And by tying the endorsement to Sandy, Bloomberg is trying to cement the idea that Sandy=climate change
The centrist agenda, as defined by Bloomberg: all Bush tax cuts expire, act on climate change, pro gun control, pro choice, pro gay marriage.”