After six weeks of intense campaigning, tens of millions of dollars worth of television ads and controversies enveloping both Democratic candidates, the much-anticipated Pennsylvania primary yielded much sound and fury while clarifying nothing.
Hillary did what she needed to do in order to continue her campaign into North Carolina and Indiana two weeks from now, perhaps through the end of the primary process in June and potentially all the way to the Democratic convention in August. She almost certainly muted any calls for her to exit the race.
Barack Obama was unable to do what he needed, which was an outright victory in Pennsylvania or at least a very narrow loss. Either scenario could have effectively ended the race right now. His failure to do so casts at least a sliver of doubt on his candidacy, his seemingly insurmountable delegate lead and near lock on the nomination.
After months of campaigning, unprecedented coverage unfathomable resources and record voter interest, the only thing that's clear in this race is uncertainty.
The cultural divide within the Democratic Party was on full display once again in Philadelphia, with support for both candidates breaking down among familiar lines of gender, race, income and education. The emergence of religion as a fault line in the state was striking. Clinton carried nearly 70 percent of the state's Catholic vote.
Those divisions threaten to drive the party to distraction. It is a race stuck in neutral with the finish line just feet away.
Mathematically speaking, Clinton has almost no chance to overtake Obama in the measurable metrics of the race. In pledged delegates and the popular vote, there simply aren't enough left up for grabs for her to take the lead barring a complete Obama meltdown.
But he cannot clinch to nomination simply with those measures either. He will still need a good number of the remaining free agent superdelegates to flock to his cause and Pennsylvania gives them more to think about.
As late as Tuesday morning, Obama was describing his task in Pennsylvania as "an uphill battle." This despite the fact that he outspent Clinton as much as three-to-one in a state that is not inconsequential. Looking broader, Obama has won more states overall, but among battleground states that will be important in the fall, only Missouri went for him. California, New Jersey, Ohio (Florida and Michigan with asterisks) and now Pennsylvania all fell Clinton's way.
Should a prohibitive front-runner face an "uphill" battle in Pennsylvania at the end of this long campaign? That is but one of the questions hanging over Obama as this race goes forward. The other will be how much have recent controversies harmed his candidacy?
Pennsylvania was not only an important battleground state, it was one which came at the end of a six-week cooling off period in the primary process. In the course of that pause, Obama was faced with controversial statement from his longtime friend and pastor Jeremiah Wright and his awkward assertion that small town Americans "cling" to their guns and religion out of bitterness. While there's little direct evidence to show that those episodes held him down in Pennsylvania, he clearly did not make any inroads among those voters who might have taken them into account, voters the Democratic nominee will need in November.
One thing is increasingly clear - Democrats who've taken sides are becoming entrenched. According to CBS News exit polls, 62 percent of Clinton voters in Pennsylvania said they would not be satisfied with Obama as their nominee while 52 percent of his voters said they would be dissatisfied with her. More troublesome, 25 percent of her voters and 16 percent of his said they would vote for John McCain in the fall if their candidate is not in the race.
Going forward, Obama's campaign is signaling that it will begin making the argument against McCain as much as continue the fight with Clinton. After a fairly solid thrashing in Pennsylvania, that might be a dangerous strategy. He will be forced to engage a re-energized Clinton in Indiana, the next make-or-break contest, and it's likely to be at high volume if not negative.
So the battle of attrition continues, with each Democratic candidate wearing down the other and still nothing settled. 'Round and round it goes. Where and how it ends, nobody still knows for sure. (This article also appears in the politics section of CBSNews.com).