by Jay Newton-Small/Scranton, TIME Magazine, USA - After one of the most negative weekends of campaigning so far this election, it's hard to know if either Barack Obama or Hillary Clinton will emerge from Tuesday's long-anticipated Pennsylvania primary looking much like a real winner. As the primary battle has become increasingly nasty, some Democrats worry that voters are digging in their heels and contemplating staying home (or even voting for John McCain) in November if their first choice doesn't get the nomination.