So what happened in Philadelphia and its suburbs?

[Orser67]

The blue areas of SEPA in the township map are either:
a)working class inner suburbs of Bucks and Delaware counties,
b)more rural areas,
c)Philadelphia

Clinton actually improved quite a bit on Obama in Chester and Montgomery counties, and basically treaded water in Bucks and Delco. Looking at that township map, it's clear that she won votes in upscale areas with lots of college-educated whites, and lost voters in working class areas with lots of non-college whites.

Unlike e.g. Milwaukee, Philadelphia saw an increase in the total number of votes between 2012 and 2016 (from 690k to 707k), but Clinton lost about 4k votes compared to Obama, while Trump gained 12k votes compared to Romney. My understanding is that Trump did better among non-college whites in South Philly and the more suburban parts of Philadelphia, especially in the Northeast (which, incidentally, has a large Russian community). Politically, the Northeast is sort of the Staten Island of Philadelphia.

[Orser67]

This area was not why Trump won the state. Trump won the state last time because he ran up the margins in the central part of the state and also did well in Erie and Luzerne counties and more counties that flipped.

Yeah, in the Philadelphia area, the Democratic margin of victory increased by about 50k votes compared to 2012, mostly due to gains in Chester and Montgomery counties. In almost every other county in the state, the Republican margin of victory increased or the Democratic margin of victory decreased (or the county flipped D to R); the only two exceptions were Allegheny County (Pittsburgh) and Centre County (Penn State).