Also with PA, Philly obviously is a big factor, but its not like it wasn't heavily Democratic when the state was lean R. It is the Philadelphia suburbs that have played a big role in the changes in the state from being lean R to lean D. Montgomery County for example when GOP in ever Pres Election from 1916 to 1988 with the exception of LBJ in 1964, hasn't gone GOP since.
Yea, it's not just Philadelphia and Pittsburg that's keeping PA from going Republican. There's a good 6 or 7 other counties in eastern PA that all have over 100,000 voters that lean more towards Democrat that the rest of the state, and their populations are growing faster than a lot of rural counties in the center and the western part of the state. In fact, over half of all PA's voters live in about a dozen left leaning high population counties. I don't think PA is going to move towards Republicans in Presidential election. If anything, they're going to move further away.
