A reader writes:
Say what you will about the Clintons, they are not stupid. They know that their only chance of winning the nomination is some of kind of major event. The fact is though the odds of this major event are greater than zero. Therefore, there is no reason for her to quit. If I was in her shoes, I wouldn't either - fate is a funny thing. Their plan is to go through all of the primaries (6/4). At that point many of the super delegates will start breaking for Obama in large numbers and it really will be over for her. At that point, she will quit and endorse Obama.
However, since this is her plan, she can't admit that or nobody will vote for her in the remaining primaries or give her money. Therefore in order to give her delegates faint hope and keep them in line now until the end, she has to talk about the convention, Michigan and Florida, pledged delegates switching, etc. This is all a smokescreen.
The JED report adds:
It was a beautiful thing to see -- because the moment a presidential candidate is forced to vow that he or she isn't quitting, you know they are toast.
It's true that Romney, Huckabee, Giuliani, and Edwards all vowed to fight until the convention and then dropped out. There may well come a point where Clinton supporters, staffers, and superdelegates decide to balk, but I wouldn't count on that happening anytime soon.