I don't think PA is a lock for anyone. And the Dem strategy is to stuff the ballot boxes (figuratively speaking) in the inner-city to disenfranchise the rest of the state. We had it happen in an MD governor's race a while ago - Ellen Saurbrey (R) was leading in the count; they held the report for one Baltimore City precinct until the rest of the state had reported and then, "What a Surprise!" - the city precinct provided the margin of victory for the D. Some Baltimore precincts show NO VOTES WHATEVER for the R.
We have to watch them everywhere.
Recognizing this activity in the specific precincts where it is occurring should make it easier to hold back their ballot counts for additional scrutiny like signature verifications.
If there is a procedure to “quarantine” the most lopsided results, it may help cleanse the process in PA.