The unemployment will sink him; he will not be the Dem candidate in 2012.
Even Jimmy Carter got his party's nomination. You can't beat somebody with nobody and it doesn't look like there's any Democrat who will challenge him.
If Hillary does, it may change things, but politicians like the patronage: so long as Obama has jobs for them and money to pass around they aren't going to turn on him.
It would be interesting if Russ Feingold challenges Obama from the left, but I don't see him losing the nomination. Democrats invested too much in him to back away easily.
-——The unemployment will sink him-——
The coming war will likely, but not guaranteed, save him