Not all Trump voters are stupid. Some really have short-term concerns that outweigh the risk to the Republic. If you really believe that Biden will make your life worse in the foreseeable future, but Trump MAY make it worse when the oceans rise or the race riots start, a vote for Trump doesn’t seem so dumb.
To some extent, worrying about the fate of the country or of humanity is an elitist luxury. I am a never-Trumper, but I recognize the privilege implicit in caring about the big picture. I don't know what effect Biden's plans will have on me personally, but I'm pretty sure they'll be tolerable. Climate change and civil unrest are greater threats to me than higher taxes or "socialized" medicine.
I have the luxury of caring whether I can be proud of my country. One of the bad things about our economy is how few people share that luxury. I don't believe that "income inequality" is a big deal, but I do believe that "income inadequacy" is a very big deal. If more people had more income, whether or not that made the uber-rich uber-richer, they could think more about keeping the water from the basement than the wolf from the door.
Congress did not always have an approval rating so low that people would turn to a literal antichrist (WE are dying for HIS sins) to save them. Yes, there is some buyers' remorse, hopefully enough to get rid of this bastard and his GOP enablers, but the electorate's real mistake was not in electing Trump; it was in electing as representative and senators candidates who say "I stopped THEM" over candidates who say "I helped YOU."