I think a lot comes back to the saying "it's the economy stupid" I'll add it's also about the money. There were another 900k +/- people filing for unemployment this week. A lot of people are seeing their jobs leaving and not coming back.
The people who were doing well, had $$$ in the bank and a secure job and skills to get another one are fine. But, there are a lot of people who are seeing their unemployment run out, having to worry about how they are going to pay for food and other things and accurately or not blaming the current administration.
I also said it a while back, with the changes to the SALT deduction there were a lot of people, outside of what people considered the "blue cities" with high taxes that took a big hit.
I have a good friend who has been a 100% Republican line voter over since 1988 voted 100% democratic in 2018 and is going to do it again in 2020. The entire community where he lives in a solid red state is now blue and that says something. Why? because it's all large private land owners. Even at dirt cheap property tax rates, due to the large plots of land they all own it was still a big number they they could write off. Now they can't and it hurt. $5 an acre for unimproved land in taxes is nothing. Until every plot is miles and miles on each side. The surrounding area also used to be red was purple in 2018, going to be interesting to see how 2020 turns out there.
Just my view.
-Dave