Democrat don’t take Pennsylvania by winning the central part of the state. They take Pennsylvania by winning Philadelphia, Pittsburg, and the suburban counties around the two. Trump is speaking to the converted. He needs to make inroads into the Philly and Pittsburg areas or else hope that they stay home like they did in 2016.
I can’t claim to predict the future but I would advise anyone against taking this next election for granted. I wasn’t surprised when Trump won in 2016 but my prediction then and now was that some supporters will tire of him and he will lose in 2020.
If you think Pennsylvanians aren’t too stupid to vote for Biden, take a look at the senators and governors they have been electing for years.
The numbers are already there. In 2016 3% of PA blacks stayed home.
Since then, Trump’s approval # has risen about 12-15 points with blacks, which I think translates into about a +3-5% actual vote gain, but equally important, an additional 10% who will stay home.
On top of this, the GOP has made a decent gain in voter registration, with a net gain of 84,000 since 2016 when Trump won.