The left assaulted Sarah because she represented the wedge issues that fueled the Bush - Rowe victories: God, guns and gays. She was an election winner and had to be destroyed. Obamachev signaled that it was OK to slime her by calling her a pig. We have to admit the campaign against her was successful.
I think McCain made a mistake tapping her with little time to prepare for national exposure. Maybe in 2012, Sarah will be more prepared.
Obamas position is very vulnerable right now. He has to tread a fine line between becoming a socialist, leftist and the moderate clintonesque rightist. It all takes just one major screw-up. It might be as simple as mishandling Iran (BTW, Iran was the Achilles heel for Carter and very well might be for Obama too). Once, people know there is a viable alternative in Sarah, they will desert him in droves. Then, it will be 1976 all over again