Tonight's debate on ABC could be the final match up between Clinton and Obama. I'm not sure really what Hillary can do to reverse her aggressive image and dominate this thing, but she needs nothing less than a grand slam to give her a shot of winning PA by more than 10 points--which is what she'll need to continue to run. Meanwhile expect Obama to hit her on the recent negative ads that she's posted in PA.
The wild card in this? Charles Gibson and the ABC guidelines of the debate that say that for 24 hours following the debate other news outlets will only be able to post up 30 seconds or less of footage. These rules give ABC and Gibson tremendous power to shape the candidates' messages in the media, and thus, should Gibson decide to throw grenades at Obama, he'll have 30 seconds to make his point. Given that Obama works best with longer more nuanced and complex arguments this can put him at a tremendous disadvantage. Hillary on the other hand is better at coming up with sound bytes, but 30 second footage can destroy her attempts to create a proper context should he play hardball with her. As usual in our political system, the advantage goes to the corporation.