How bad off are progressives in the U.S. right now? I'll go through the main paths for the immediate political future, assuming no catastrophe:
1. Obama loses in 2012.
In this case, it will all be progressives' fault, because they didn't support him enough. The left wing of the party will be blamed for everything the Republicans do for the next four years.
2. Obama wins in 2012.
In this case, he'll have demonstrated that he can insult his base and it doesn't matter because he doesn't need their help. No one will ever bother listening to progressives again.
3. Obama is primaried from the left in 2012 and wins the primary.
In this case, he'll actively bear a grudge against progressives. He's already shown that he's a lot more angry at them than at the GOP. Is he the type to let his personal vanity affect politics? Sure -- he just did.
The left is then stigmatized as a group of losers who weakened the party by splitting it, after which go to 1. or 2. above.
4. Obama is primaried from the left in 2012 and loses the primary.
This is the best outcome for progressives, certainly, but it's almost certainly not going to happen. If it does, then the new candidate wins or loses the general election. If the new candidate to the left loses, 1. above gets especially bad. If he or she wins, well, again that's the best possible outcome, but seems very unlikely. And in that case, assuming that there is still significant centrist support for Obama -- he's still a popular President -- there really will be a split in the party.
Wow am I glad that I bailed before this happened.