New York City Mayor Michael Bloomberg endorsed President Obama for reelection Thursday, while the country is watching Bloomberg, Obama, and New Jersey Gov. Chris Christie work together to clean up after Hurricane Sandy. But Bloomberg didn't endorse because Obama convinced him, he did it because Vice President Joe Biden did. Politico's Mike Allen reports Biden and Bloomberg have been friendly a long time.

The V.P. had called the mayor over the weekend, and the had talked several times this week about Sandy. Then yesterday morning, Biden was in Davenport, Iowa, about to go to church for All Saints' Day. Finally, he made the ask, nudging Bloomberg toward the endorsement: "Mike, there's too much at stake. We really need you to do this." And the mayor did.