As I write this at 10 p.m. on the left coast, the Drudge Report website is reporting that Clinton beat Obama in Pennsylvania by nearly 10%, with 99% of precincts reporting. Winning by double digits was identified by several pundits as the threshold Clinton would have to achieve in PA to cast serious doubts about the viability of the Obama candidacy. You could argue, and I'm sure she will, that she accomplished her goal in PA.
As a result of today's results, Clinton will stay in the race for the next two weeks until the next round of primaries in IN and NC. With African-Americans making up a large proportion of Democratic voters in NC, Obama is expected to win that primary. Indiana, on the other hand, may be sufficiently similar to PA and OH that we'd expect Clinton to win there. Once again, the question will be "Will she win big?"
The other big question coming out of this protracted Democratic primary battle is the extent to which partisans of one will vote for the other if their preferred candidate loses? Several polls have reported a relatively widespread unwillingness to do so. Let's try a thought experiment.
Suppose Clinton convinces the super delegates to select her instead of Obama, when he leads in regular delegates. Do you believe African-American voters will turn out in large numbers to vote for her? I doubt they'd vote for McCain but they sure could stay home, withholding their votes.
Imagine, on the other hand, that Obama attracts the super delegates and is selected. Do you believe that Clinton's core supporters, older white blue collar voters, will bring themselves to vote for an African-American intellectual? [E. J. Dionne here is comparing Obama to Adlai Stevenson.] I can envision substantial numbers of Clinton voters deciding to vote for McCain, as they did for Reagan.
In this article, Wall Street Journal editors opine that Democrats want to win the presidency too strongly to stay home or vote Republican. I happen to think they are wrong, for the reasons sketched above. Time will tell....