Sen. Barack Obama's bus tour of Pennsylvania "will alert the political universe that he is indeed making a run at a state that some thought he might duck," the New York Times reports.
"Certainly for Mrs. Clinton, it is do or die. For Mr. Obama, the mission is less stark but no less urgent. A strong showing, if not a victory, would keep his accumulated lead in delegates and in the popular vote more or less intact. And it would puncture Mrs. Clinton's argument to superdelegates that he is a flawed candidate who cannot compete in the big closely contested states."
Said one Obama backer: "We win if we lose by only five points. The immediate goal is for us not to lose by 10 points. But if she loses by a point, she's out."