I am definitely not on the "demographic trends make a Blue Pennsylvania inevitable" bandwagon [historians don't really do inevitable] BUT @cinyc9 shared a cool map of population growth & loss 2010-2019 so I had to mash it up with @4st8's PA regional map... https://twitter.com/cinyc9/status/1263516323113508864

Map is population change, not politics. Blue areas have lost pop over last 9 ys; red have gained. You see why SCPA as battleground is the 2020 hill @4st8 will die on. It's not that seats there are yet going to flip; it's that any SCPA margin changes have growing statewide impact

And here is recent political change, from @JMilesColeman. So, I repeat, demographic trends don't make anything inevitable. But if you are the PA GOP looking at these two maps together, it's hard to believe you're sleeping easy...