If Obama is going to keep this election close, or pull off a shocking upset, he needs a huge turnout from Philly and its suburbs. And it isn’t going to help if machines are malfunctioning all over the city, leading hundreds of people to leave the polls before they get a chance to vote.

Here’s Politico’s analysis:

Obama should be aiming for at least 55 percent turnout in African American wards in Philadelphia, 60 percent in the upscale white neighborhoods of Center City Philadelphia, and 70 percent in Lower Merion, the wealthy Philadelphia suburb with large numbers of highly educated and increasingly liberal voters.

The best indicator of the level of Obama support among younger voters—a group pollsters worry may not have been captured in recent surveys—will be turnout in places like State College, home to Penn State University’s main campus, or the precincts around smaller schools like Muhlenberg College in Allentown.

Another key is to look at the results coming out of Allegheny County where Pittsburgh is located. Most pollsters are predicting that Clinton will win narrowly there, but I don’t think she will. Part of her problem is the surge of new voters. Obama wrapped up his campaign last night at the University of Pittsburgh with the most impressive speech I’ve seen him make in this whole campaign. It was spellbinding and he was at the top of his game. If these new voters turn out in numbers, I believe Obama will carry Pittsburgh.

There are 567,000 registered Democrats and 250,000 Republicans in Allegheny County, and since November, there are 12,100 new registered Democrats and 3,667 new registered Republicans.

There have been 17,755 party changes since the November election, with the majority of those — 14,149 — converting to the Democratic party, and 2,174 going over to the GOP.

To sum up: Democrats in Allegheny County have added 25,587 voters, while Republicans have seen their numbers dwindle by 2,007.

In 2002, there were 175,000 voters from Allegheny County in the primary between Bob Casey and Ed Rendell. That worked out to a twenty-eight percent turnout. With 26,000 new Democrats in the county, almost all of whom are likely to vote, and sixty-two percent of whom are likely to vote for Obama, I see Obama doing well there.

Another place to look is Centre County, the home of Penn State’s main campus and not much else. Penn State Students for Barack Obama changed the game by registering 5,400 students.

Penn State Students for Barack Obama registered 5,400 students as Democrats? How many did Hillary’s group register? Here’s a little perspective. In the 2002 gubernatorial primary between Ed Rendell and Bob Casey, here were the results for Centre County, where Penn State resides.

Ed Rendell 3,971 52.5%
Bob Casey Jr. 3,597 47.5%

It’s hard to see how Obama can lose there with that kind of registration effort.

One other thing to keep in mind tonight…

The first returns are likely to come in from Philly and its suburbs, and they will show Obama well in the lead. But as the night wears on, that lead will narrow continuously until it, most likely, vanishes. Don’t get too excited by early returns.