Today is the Pennsylvania primary, where Barack Obama and Hillary Clinton face off in the first primary in 6 weeks.

The RCP poll average has Hillary up 6% against Obama. Looking at the polls, with one outlying exception, Obama’s support in PA appears to be capped in the low 40s. Meanwhile, Hillary is consistently anywhere from 5-10% ahead.

We saw that late deciders had broken for Hillary in previous contests—this seems likely to hold true in PA as well. There are a small amount of late deciders in PA (less than 10%), but that’s enough to potentially swing Hillary into a stronger finish.

Obama seems capped at the low 40s, and that’s been a constant through the race. Hillary has the most chance at an upside by appealing to whites, Catholics, and men. Obama, as always, will convincingly win blacks, younger voters, and the wealthy.

In the end, my prediction a Clinton win—50% for Hillary, and 43% for Obama. There’s always the chance that this race could be a shocker and Obama could pull ahead, but none of the polls seem to show that. The most likely outcome is Hillary gets a victory, stays in the race, and the Democrats continue to battle for the nomination. Unless Clinton dramatically loses the next few races, the possibility of this race being settled in Denver will remain.

American Research Group‘s latest Pennsylvania poll shows a dramatic swing in the Democratic primary race from a 45-45% tie early this month to a 20-point Clinton lead this weekend. Could this be the turnaround for Hillary? If electability was what matters, yes, but electability is not what the Democrats are looking at in this race.

There have been many on the Democratic side calling for Clinton to withdraw from the race. In the end, Hillary Clinton may have made the right tactical call in hanging on as long as she has—the longer Obama goes under the spotlight the greater the chance of him saying something that would land him in trouble. Even though Hillary has made her own mistakes, nothing she’s said has been as destructive as Obama’s comments. Even though the electoral tide is still against her, by Denver it is possible that Hillary could come into the convention with a credible case for the nomination. Obama may lead in elected delegates, but he won’t be able to win without the superdelegates any more than she will. If Hillary leads in the popular vote when all is said and done—and that is quite possible—are Democratic superdelegates really going to vote against the majority of Democratic voters?

On the other hand, it’s not as though Hillary Clinton is a woman of the people either. Both Clinton and Obama grew up arguably middle class, they have a record of associating themselves with the academic elites. Clinton is hardly the poster child for a campaign against liberal condescension. Her outright falsehoods about sniper fire in Bosnia and her record during her husband’s Presidency don’t help her image.

The Politico has an excellent article on what Clinton wishes she could say, but can’t do so without jeopardizing her own candidacy:

There’s nothing to say that the Clintonites are right about Obama’s presumed vulnerabilities. But one argument seems indisputably true: Obama is on the brink of the Democratic nomination without having had to confront head-on the evidence about his general election challenges.

That is why some friends describe Clinton as seeing herself on a mission to save Democrats from themselves. Her candidacy may be a long shot, but no one should expect she will end it unless or until every last door has been shut.

Skepticism about Obama’s general election prospects extends beyond Clinton backers. We spoke to unaffiliated Democratic lawmakers, veteran lobbyists, and campaign operatives who believe the rush of enthusiasm for Obama’s charisma and fresh face has inhibited sober appraisals of his potential weaknesses.

The Politico article is right—Obama has not taken the kind of lashing that he will invariably get in the general election. The Clinton camp can quite credibly claim that if Barack Obama gets the nomination, he will lose in a landslide. The Democrats will do very well with urban professionals and African-Americans, and lose rural voters, women, Jewish voters, and Reagan Democrats. Beyond the Obama hype lies the cold reality of the electoral math: and all Clinton needs to do is carry the states that Kerry won in 2004 and win one swing state like Ohio, Florida, or Nevada. What states has Clinton done well in? Ohio, Florida, and Nevada. The electoral math favors Clinton, and the Clinton camp knows it.

Despite all this, Obama will still get the nomination. The Democrats are increasingly young, liberal, and affluent. Obama appeals to the New Democratic Party, while Hillary Clinton appeals to the old. Hillary Clinton, much to her dismay, is not the face of American liberalism today. It is hardly shocking that outspoken liberals who want to see America remade in the “progressive” image are flocking to Obama. He’s one of them.

The fact that this is a recipe for electoral disaster is not a factor in the Democratic race. Democrats voted with their heads rather than their hearts in selecting John Kerry in 2004 on the basis that Kerry was “electable.” Barack Obama is Howard Dean without the crazy and with the added benefit of being someone who can play to the African-American base of the Democratic Party. Even though Clinton probably has the better argument on electability, she’s winning the wrong contest. The Democrats don’t want electable, they want someone who represents what the Democrats want to be: a party that is unabashedly liberal wrapped in the mantle of “progressivism.” Obama is comfortable with the Daily Kos set, and it is that demographic that now controls the Democratic Party.

Obama has definitely hurt himself and that gaffe undoubtedly will help Hillary Clinton carry Pennsylvania, and perhaps win the popular vote. Yet the heart of the Democratic Party is understandably with Obama, and even though Clinton is the more electable of the two, electability is not the factor that will influence who will win the nomination this year.