It is way early to think about 2012, but I don't think Obama is the underdog even given his declined approval ratings. Once health care passes he'll claim victory. Never overestimate the intelligence of the public or the media. Once health care passes, everyone is going to wake up the next day and discover the heavens didn't fall, and nothing much has changed. In fact not much kicks in for several years anyway.
Many talking heads will be calling this an "historic" accomplishment, and he'll be back up there with Teddy Roosevelt and LBJ. He is smart to be talking tough on Al Queada, and will continue to do so. Sec. of Defense Gates just signed up for another year so that is a plus, and I don't think the Dems will take a terrible hit in 2010. In fact with
Chris Dodd out, there is a better chance the seat in Connecticut stays in the D column.

Bottom line is this: IT THE ECONOMY STUPID! If we are at 10% unemployment and people are still losing their homes in 2012, then he is in trouble.

Still who will the GOP run? IMHO their strongest candidates would be reasonable right of center people like Tom Ridge. Mitt Romney is a tad flaky, but electable. However if the teabaggers start splitting off from the GOP, and the party is split, Obama can get reelected with less than 50% of the vote.