The state of the economy is considered the main determinant of presidential approval; Bernstein takes a stab at why politicians bother governing at all:

No, Barack Obama will not win any votes if he manages to "win" in Afghanistan, whatever that actually means.  But he'll lose plenty of votes if Americans continue to die there in ever-increasing numbers.  He'll also lose votes if Americans leave, the Taliban takes over and shelters bin Laden, and that allows more devastating terror attacks (followed by another invasion, followed by more US casualties).  Turning closer to home...as far as I know, the administration did an absolutely terrific job of responding to the swine flu last year ...

So, who is voting for the Democrats this year or generally supporting Obama because he or she didn't die horribly in the prevented horrible pandemic of 2009-2010?  Well, nobody; no one even remembers last year's flu scare, (perhaps) because successful government action turned it into a non-story.  But if things had gone wrong, people would have blamed Obama and, beyond that, people would have been more unhappy about everything, which tends to hurt incumbents.

We want to hear what you think about this article. Submit a letter to the editor or write to letters@theatlantic.com.