I don't want to add to the narrative that the Clintons just won't stop. That's unfair because all politicians campaign to win, and they only stop when they must. But it is nevertheless peculiar that we seem to be operating in two parrallel universes. In the mathematical one, Barack is close to wrapping the nomination up. In what others have termed a "psychological" war on the remaining unpledged superdelegates, Obama's Reverend Wright controversy has made the nomination race too close yet to call.
I think the real world is the mathematical one. Obama only needs about a third to half of all remaining unpledged superdelegates to go his way. So I join Dick Morris in saying that it is over. If so, then we need a reason for why Hillary is waging what others have deemed a psychological war with the remaining unpledged superdelegates. Surely, though she must not show signs of realizing it, she must know that her chances even with the Wright windfall are abysmal.
It is rather too sinister to think that Hillary Clinton is trying to ensure Obama's defeat to McCain in November, so I offer instead a slightly less cynical evaluation. Hillary Clinton simply wants to end on her terms: and that is to force Barack Obama to offer her the VP slot just like everyone knows that if she wins, she would be obliged, on pain of a repeat of 1968, to offer the slot to Obama. Now she'd probably not take it, but to secure her position as heir apparent in 2012/16, Obama must be forced to offer it. The psychological war isn't about winning the present nomination any more; it is to find a way to "concede" the present battle in order to win a future war. It is precisely at the point at which she threatens the dissolution of the Democratic party that she will pull back and stand behind Obama. At this brink, others will say that she has been maximally destructive; she will think she has been optimally positioned. Both sides will be correct.