Many Pennsylvania voters acknowledged the negative tone in the campaign, according to preliminary exit poll results. However Clinton is bearing the blame — two-thirds of Pennsylvania voters in preliminary exit poll results say Clinton attacked Obama unfairly; fewer, but still about half, also say Obama unfairly attacked Clinton.
While some party officials are wringing their hands about the bitter tone of the Democratic campaign, worried it will turn off independents and undecided voters and damage their chances against Sen. John McCain, R-Ariz., in the fall, others say despite the tone, voters mobilized to overturn eight years of the Bush administration and will rally behind either candidate if they win the nomination.
"A majority of Americans believe this country is headed off in the wrong direction," Devine said. "As long as [those] issues tend to dominate the electoral landscape, Democrats will have a real advantage."
ABC News' deputy political director Teddy Davis, Gary Langer, Nicole Gallagher, Sunlen Miller, Eloise Harper, Sarah Amos and Nitya Venkataraman contributed to this report.