By all accounts the race for Pennsylvania is close. Too close. Hillary Clinton needs to score double digits tonight to stay in the race. Cue the ad featuring Osama Bin Laden.

The genius of the ad is that it doesn’t mention Barack Obama at all. Instead, it’s a montage of ‘testing times’ like the bombing of Pearl Harbour, the Wall Street crash, ominous shots of petrol bowsers, a quick stock footage snap of Bin Laden and then a scary looking building with the windows smashed out and a foreclosure sign out the front. Overlaid with a voiceover worthy of a preview for Die Hard 4, it quotes President Truman, “If you can’t stand the heat get out of the kitchen” and then poses the loaded question “Who do you think has what it takes?” Thus, the theory goes, sowing seeds of doubt into the minds of undecided voters across Pennsylvania …

Roll out the attack ads: Today’s polling indicated a slight upward trend for Senator Hillary Clinton in Pennsylvania, with most numbers tacking above the margin for error. Still, there might be something to the rumors that tomorrow’s primary is expected to be a tight contest, and the clearest sign that the Clinton campaign is taking that seriously is that they’ve released a new thirty-second ad called “Kitchen,” which “detail[s] how tough the job of President is…asking voters who they think is ready to step in and handle it.” And, hey! Look who makes a cameo appearance! None other than stock footage of Osama bin Laden, presumably on loan from the defunct Giuliani campaign. — The Huffington Post

Chasing double digits: Senator Obama has another opportunity tomorrow in Pennsylvania – and this time he doesn’t even have to win. If he simply outperforms the latest RealClearPolitics Average which has him trailing by 5.9%, that will be enough to calm nervous superdelegates while all but eliminating any hope Senator Clinton has of claiming a popular vote victory. Senator Clinton has a much higher hurdle. With time running out and Democrats increasingly anxious to turn their fire on John McCain, a win by 2-4 points along the lines of New Hampshire and Texas will simply not get the job done. Hillary Clinton needs a double-digit win. — John McIntyre, RealClearPolitics

Hillary’s challenge: To overtake Barack Obama in the nationwide popular vote, Hillary Clinton needs a bigger win in tomorrow’s Pennsylvania primary than she has had in any major contest so far. And that’s just for starters. After more than 40 Democratic primaries and caucuses, Obama, the Illinois senator, leads Clinton by more than 800,000 votes. Even if the New York senator wins by more than 20 percentage points tomorrow — a landslide few experts expect — she would still have a hard time catching him. — Bloomberg

A degrading debate: A Last Wednesday’s two-hour televised smackdown in Philadelphia between the two remaining Democratic candidates for President, which might have been billed as the Élite Treat v. the Boilermaker Belle, turned into something worse—something akin to a federal crime. Call it the case of the Walt Disney Company v. People of the Commonwealth of Pennsylvania (and of the United States, for that matter). Seldom has a large corporation so heedlessly inflicted so much civic damage in such a short space of time. None of the other debates had been models of philosophic rigor. But, right from the start, there were clues that the sponsor of this one — ABC News, a part of the ABC network, which is owned by Disney — might establish new benchmarks of degradation. — Hendrik Hertzberg, The New Yorker

Why Obama’s missteps are a big problem. Obama Republicans could produce a Democratic presidential landslide. But Obama’s current missteps jeopardize their support and imperil his election. These apostate Republicans never were deluded into considering him anything other than a doctrinaire liberal who wants a more intrusive government with higher taxation and tougher regulation. But they have leaned toward him as an exceptional candidate in the mold of John F. Kennedy and Ronald Reagan, a post-partisan leader and a welcome contrast to George W. Bush’s failed presidency. That impression is threatened by Obama’s performance the last 10 days, climaxed by Wednesday night’s debate with Hillary Clinton. — Robert Novak RealClearPolitics

McCain is the real winner: While Clinton and Obama fight it out, McCain stays above the fray looking like a leader, even a president. He can follow a script that he’s created rather than one dictated by his opponent. He can give big, serious speeches and avoid journalists’ questions about polls and process. McCain’s recent improvement in the polls all but destroys the argument, made by some immediately after he locked up the Republican nomination, that he would be hurt by the lack of media attention. He is polling better because he isn’t part of the daily Democratic squabble. But this dynamic is likely to change when Democrats finally have a nominee, whether it is in May or June, or even July. And at that point, the going will get tougher for the de facto GOP nominee. — Stuart Rothenberg, The Rothenberg Political Report