At this point, it's pretty much mathematically impossible for Clinton to win more pledged delegates than Obama. See for yourself using this nifty calculator:
http://www.slate.com/features/delegatecounter/
She has to win
every remaining state by a massive 62-38 margin (not gonna happen) to pull ahead by a mere 3 delegates. If someone can play with that calculator and come up with a realistic scenario by which Hillary can pull ahead, I'd love to see it.
Her only chance now is to influence the superdelegates to break her way in addition to somehow getting the Michigan and Florida results to count.