For the first time, a poll is showing Senator Obama with a slight lead over Senator Clinton:
Barack Obama 45
Hillary Clinton 43
Obama's steep rise could be a reflection of a growing sense among Democratic voters that a continued divisive nomination process will hurt the party's chances of defeating John McCain this fall. An Obama upset in Pennsylvania would be virtually certain to force Clinton out of the race.
Obama has his customary large advantage with black voters (75-17) and is keeping it relatively competitive with white voters (49-38)