I don’t know much about Roberto Unger other than what I read on his wiki page but he and I (and a few others like Matt Stoller and Ian Welsh) seem to have arrived at the same conclusion through independent means. Obama must lose this election, or, if the Democrats want to save themselves, must not be allowed to run in the general election.
Check out this video from Unger released yesterday. What I think he is calling for is a modernization of the left while adhering to democratic and progressive principles. He comes right out and says we must defeat Obama in order to save the Democratic party in the last 3 minutes and his argument is very compelling. It’s a little like curing syphilis with arsenic but unless the Democrats quickly realize the danger they’re in, we may not have another choice.