Where it is going to hurt the Dems will be in the Dem's hollowed out cities. These people at pissed at the Dems and know they dare not say anything lest they be beat up or worse. Some may even take up some of these phony mail in ballots and fill a bunch for Trump just to try to get even with these Sickos.
IMHO: The Dem cities are going to take a long time to get back to what they were if ever. Some are simply going to fail (as was the intention of the party). Pelosi is fighting for city bailouts but it is not going well.
I was in Philadelphia in late 2016, and was shocked to see many Trump 2016 signs everywhere. People in cars tooting their horns as they drove around with Trump signs on their cars. And the people I encountered were giving a thumbs-up for Trump. That was shocking to me, as I always thought Philadelphia to be solid Democrat. I think many will vote for Trump in 2020, again.