Pennsylvania is pretty much like every other 2020 blue state (with a few exceptions in New England) in that the urban areas vote blue and the rural areas vote red. In PA, the eastern counties from Philly going north bordering New Jersey are urbanized and vote blue, as does the Harrisburg area, that big county in the middle of the state containing State College, and Erie and Pittsburgh (Biden won Pittsburgh/Allegheny County 60% to 40%.) It's less an east/west split than an urban/rural split just like Ohio and North Carolina and Wisconsin and Georgia and Arizona and Michigan and on and on.