I made a super long post the other day in the "Active Measures . . . Propaganda" thread that I won't copy here, but I agre 100% that propaganda is at work. What I think people aren't comprehending is that it is not disinformation per se, it is the pervasive demonization of liberals since the 1990's beginning with conservative talk radio to Fox News to today with all of that plus podcasts and a proliferation of information sources that, as noted above, are coordinated to amplify eachother and to enforce echo chambers.
I'm a former conservative/republican voter and still run in a lot of those circles. We have gone from a time of good faith debate to today when every attempt to talk about it ends at "yeah but liberals are trying to destroy the country." No amount of insanity, stupidity, racism, hate, crime, and treason from Trump could break through that simple message that has been pushed for decades and has poisoned more than half the electorate.
I think one solution would be to try to make propaganda a topic in the conversation. HIghlight studies like the one mentioned above showing conservatives favor democrat policies when they are presented without , put out documentaries about propaganda affecting americans, keep spreading the word. If enough people realize they are being conned, they won't go back to voting that way. If we don't, democrats will end up trying to change in ways and fix things that aren't really the problem, and voters will keep ping ponging back and forth when they get pissed enough.