What are we up to on the GCB? D+9?
PA was basically tied at D+2 in 2016. In a uniform swing environment thus the state would be expected to vote about D+7 or D+8 based on that. The Governor's race would have a bigger differential than the Senate race obviously and the same thing occurred in 2006.
Casey outperformed by about 5% to 6%, which based on his name id, popularity in the NE and Lehigh Valley and yes record performances in the cities and the suburbs, makes a lot of sense.
I think PA is a close to even state with the national average, it is the front lines between the two demographic blocks of each party and it is a tendency to favor incumbents as someone said. There certainly was a turnout problem for the GOP as the electorate that showed up in the exit poll was Clinton by 6. While we cannot be certain as to the accuracy, there is reason to believe it might be higher than that based on the turnout data posted above but it is certainly in the ballpark.
Still for a state that turned out in a manner hostile to the President, it still was split close to even on trade and immigration policy. A plurality said Trump's trade policies help more than they hurt IIRC and the split on immigration between "too tough" and "Just Right/Not Tough Enough" was 52%-48%. this number appeared elsewhere in the exit polls as well.
PA looks a bit like the Dem version of NC after this year. It swings to narrowly support the new president, but the party that seems to be doomed demographically is able to fight back a lot better than expected because their base areas haven't been maxed out yet. It's almost certainly the best medium/long term Dem prospect of the Obama-Trump states.