Jules Witcover: Beating up on Washington

As Pennsylvania Democrats go to the polls today to weigh in on the nomination fight between Hillary Clinton and Barack Obama, the atmosphere has distinctly turned negative.

It represents no change in Clinton?s posture as she scrambles to cut into Obama?s narrow lead. But as his campaign has taken some hits, his strategists apparently have decided he?d better climb down off his pedestal as Mr. Clean above the fray.