In particular, Obama's insistence on compromise and unity has led him to some pretty terrible anti-progressive positions. Let me put it crassly and wildy overstate things for the sake of argument: if Jamie Leigh Jones was being raped 4 times a day, and some folks wanted it to stop, while others didn't have a problem with it, then Obama's compromise position would be to ratchet down the rapes to just 2 times a day. Compromise. Unity. Everybody's happy.
If you compromise with a corrupt and morally bankrupt system, you're not compromising, you're capitulating and abetting. End of story.
Or, to put it more tactfully, as Mizner does:
[Obama's] selling unity and hope, yet what he's proposing to do wouldn't create much of either. It's progressive policies, not good intentions or expressed desires, that create unity and hope. Obama wouldn't even roll back Bush's tax cuts for the rich; he'd keep them in place until they expire in 2011. Very unifying. The unacceptable status quo--in which the powerful are way too powerful--will only be strengthened if it is ratified by a black "liberal" president. That's my fear.[Emphasis mine]