Barack Obama's in trouble because of his association with Donnie McClurkin, a black Southern preacher who vilifies gays. This has of course angered gays and lebians, who now want Obama to disassociate himself from McClurkin who is loved by vast numbers of South Carolinian black voters, who are key to Obama's electoral plan to beat Hillary.
Obama has repudiated McClurkin's bigotry, reaffirmed his absolute support of gays and lesbians, but has not spurned McClurkin. And now he runs the risk of alienating not only gays and lesbians, but liberals who have always suspected Obama wasn't liberal enough. This may all be academic, because until he does something dramatic, Obama remains the 30-point underdog with no chance of winning.
But there is something worth noting here, because this dynamic is prevalent throughout Democratic politics. We liberals hold two simultaneous, conflicting values that we haven't ever had the courage to examine closely. On the one hand, we think we are the open-minded altruists who welcome everyone into our big tent; on the other, we are a coalition who value fidelity to our issue(s) above all else. So we want everyone in our big tent until they don't agree to back our issue, and then we're not so high on the big tent, anymore.
The single-issue folks have been ascendant since the 70s, and when candidates run for office, they must make a big show of bowing to each of these calcified interests lest they find themselves the target of a bitter crusade. The single-issue focus seems like a good way to accomplish those ends, but it has been a big loser for environmentalists, social justice activists, abortion rights activists, etc. In ignoring (or worse, targeting) other potential coalition partners, Sierra Club, NARAL, unions, and so on have made themselves a yappy minority, of no more consequence to the German Shepherds of the GOP than a dachshund.
So now the Obama coalition splinters. A helluva way to get a guy elected.