Obama started to blow it here with his infamous “bitter clingers” comment in ‘08. That was directly aimed at residents of this Commonwealth.
Then his campaign made the inexplicable decision to write-off white working class voters over a year ago. Whenever the Dems win here that is the group that carries them to victory.
Pile on the fact that he has declared war on Catholics, Coal and the Shale Gas industry, and things are shaping up pretty badly for him.
Plus he further alienated those white blue-collar voters with the Skip Gates controversy, Philly Black Panthers, and Trayvon Martin, indicating that Obama had already chosen up racial sides. They’ll never tell a pollster but that scares the crap out of them.
An underrated factor was the passing away of John Murtha and the disappearance of his district. It was filled with Bitter Clingers to lean Conservative, but kept voting Democrat because the only jobs available depended on his ability to divert Federal monies. He is gone, those jobs are leaving, and it’s become a non-issue.
Barone makes a good point that affluent suburban voters, heavily present in PA, are deserting Obama in droves.