my theory on the large number of Pennsylvania Provisional Ballots
I haven't been able to monitor the news as closely today as in previous days, but every time I've heard talk about the large number of provisionals in PA, the favored theory has been that perhaps these would favor trump because republicans might have requested mail-in ballots early in the process but then, as the mail-in process became politicized, decided instead to vote in person. If they then went to the polling station but didn't take their mail-in, they would have had to cast a provisional ballot.
It seems to me to be just as reasonable to speculate that the large number of provisionals would be democrats who tried to vote by mail but did so fairly late in the process and then, because of the fear in the week before the election that the USPS was unreliable and the confusion about the court rulings with the late arriving ballots and so on, decided to cover their bases and vote in person as well. And if they had already mailed their ballot, they wouldn't be able to surrender it and would have to vote with a provisional.
Anyway, that seems pretty logical to me. And again, maybe it's been brought up, but all the speculation I've seen has been the former, trump-friendly scenario.