Casey neutralized too many of Santorum's advantages in the west among conservative Democrats, and in the T to a lesser extent. He took the abortion and the gun issues off the table and combined that with an incredible name ID. In short, Casey gave many Democrats a reason to come home.
Santorum was also hurt by the stories about him possibly running for president, and the issue with his kids and going to school in Virginia. He looked like he was getting too big for the state. In that atmosphere, Casey couldn't have been a better foil.
I don't know how Santorum tried to cultivate a relationship with voters in SEPA, but I think he probably should have paid more attention to that area. They may not like his pro-life stands, but Santorum ought to have stressed other issues that he and moderate Republicans agree on, like taxes. In general, Republicans need to watch these moderate suburbs. They've been going south for them, and that's not good.
In general, I think Santorum lost his rapport with PA voters. Something goes wrong when you get flushed out of as many areas as he did. I don't know how he could have won, but he didn't seem to have his pulse on what the voters were thinking.
Tax cuts for the very wealthy weren't exactly on the minds of SEPA voters as the most important issue or issues heading into the midterms last year. Wouldn't have mattered how much Santorum tried to play and push that card. His social views, his views on Iraq as well as being a very close ally of Bush destroyed him there.
