I derided the media polls for their assumption of what did, in fact happen: That blacks, Latinos, and young people would show up in the same numbers as they had in 2008. I was wrong. They did.

But the more proximate cause of my error was that I did not take full account of the impact of hurricane Sandy and of Governor Chris Christie’s bipartisan march through New Jersey arm in arm with President Obama. Not to mention Christe’s fawning promotion of Obama’s presidential leadership.

It made all the difference.

A key element of Romney’s appeal, particularly after the first debate, was his ability to govern with Democrats in Massachusetts. Obama’s one-party strident approach, so much the opposite of what he pledged in his first national speech in 2004, had turned voters off. But by working seamlessly with an acerbic Republican Governor like Christie, Obama was able to blunt Romney’s advantage in this crucial area.