South Dakota and Montana can't get him there but Barack Obama is just about over the line in his pursuit of the Democratic nomination. But is Hillary Clinton unveiling a new end game? Most of the talk about how close Obama is and how Hillary can't win is premised on the understandable assumption that superdelegates who have announced the support for him are somehow irrevocably "his."
It's a good working assumption but, of course, it's not true. "Obama" superdelegates are perfectly free to change their minds. The public debate over what they ought to do (reflect Obama's lead among the committed delegates or follow a mythical national "popular vote" which can itself be measured in multiple ways) doesn't much reflect what they should and will do.
The whole point of having uncommitted superdelegates is to allow supposedly seasoned professionals to make a judgment about what is in the best interests of the party independent of what the voters have done in the state primaries. At this point (and contrary to my own earlier assumption), it appears that Hillary is a somewhat stronger general election candidate than Obama. It's not clear that her advantage is clear enough to warrant a reversal of the party's movement toward Obama as its voters are increasingly moving toward Clinton.
But even if it was, the Democrats are in a box. Dumping Obama would threaten to break the modern connection between African-American voters and Democrats. These voters have come to believe (with some justification) that Obama has earned the nomination and that taking it from him would be an act of disrespect toward an important constituency. Without African-Americans, the Democrats can't win. Ever. Even if, given the likely identification of Obama with far left politics, Clinton is the stronger candidate, there is no choice to be made here.
That's why its over and has been since Super Tuesday.