Democrats in PA are voting by mail in much more significant numbers than Rs. Where this could get problematic, is if this is done at a large scale in November. In person ballots are counted before mail in ballots. If the GOP is voting in person more, their votes will be tallied on election night. Dem mail in ballots will trickle in over time.

So if we extrapolate this PA data on a national scale in November, we could expect a scenario where the GOP is ahead, perhaps even comfortably, when in person votes are counted. But Dems will hold a significant advantage on mail in votes simply based on volume, and the Dems could storm from behind well after the fact.

I’m sure that very plausible scenario would go over well with Trump and his base.