By the end of the primary season, neither candidate will have enough ‘Pledged’ delegates to win the nomination. Obama is leading, but leading is not enough to win. The Super Delegates will decide the nomination.
Who will they go for? They will likely go for the ‘perceived’ winner.
As of now, the pledged delegate count and the popular vote are within ~1-2%, with Obama leading both.
If HRC wins Pennsylvania, she will still be behind in the delegate count, but she will likely take a popular vote lead. She will also have taken most of the big Electoral College states. She will also have officially taken two out of the three BIG problematic states for Dems: Ohio and Pennsylvania. Florida being the third. (She’ll argue that she won that also!) This may be enough for her to be the perceived winner.
If BHO wins Pennsylvania. He will have the delegate lead, the popular vote lead and one of the problematic states. That should be enough to be the perceived winner. But Florida may then come back into the equation. Each will have won one of the three big ones. The winner of the Florida delegates will make it 2 out of 3.