The problem isn't Obama; it's the national Democrats, who as a group have become the Whigs of our time. They've become detached from their working and middle class base, they don't know who they are, and they have no passionately held principles or moral compass. They're wimps in a knife fight for the soul of the country.
So sure, we have to vote for them, because to vote for the other guys is to regress the country according to their Social Darwinist agenda, and a Dem in office will at least slow that down. But the bottom line is that the Republicans know who they are, and in a war for the soul of the country the progressive left has no organization that can match GOP passion and conviction.
In the 1850s serious people with passionate convictions threw the feckless Whigs under the bus and formed a new party. Sooner or later serious people in our own time will have to do the same to the neoliberal-dominated national Democrats. The Greens are serious people, but they do not now have a serious party. They could, however, be part of the formation of one someday. The part that's missing now comprises the element essential to broaden its base--people whose progressive convictions are rooted in their religious convictions.
I don't expect that kind of alliance to happen any time soon, but IMO, it's what has to happen if there's any chance of pushing back against the GOP flood. Until then we throw more sand bags on the levee, for that's all voting for Dems accomplishes, but maybe it will buy us some time.