When Barack Obama is on the stump, his whole point is that if we can just be unified, public policy issues don't really matter, what really matters is unity -- that sort of thing.
There's also a sort of contempt for Democratic values that also comes out of this unity thing. One of the most fascistic things that kids on college campuses say is that, "If you're not part of the solution, you're part of the problem." In other words, there is no safe harbor. Either you agree with where the movement wants to go or you are a problem and problems need to be solved by definition.