It's large in part about creating an enemy. We can't be opposites, we must be enemies. Rewind 15 or so years ago, the Democrats were painting a picture of Bush (including the Republicans but moreso Bush) as, perhaps a little evil, but mostly inept. Not quite an enemy.... but close. The Trump era has been all about creating a threatening enemy. Trump's propaganda is really strong, simple, effective. Yes the R's in the 2000's were touting the threats to society by the D's, but it was mostly weaksauce arguments. Maybe because of the change in effectiveness is why they are all so willing to back Trump even today?I think it's down to a few factors, his TV show, the fact he lives on Burgers and Coke and possibly that he is as racist and bigotted as they are.
What they fail to grasp is that he despises them as low class, witness his comments about theose 'supporters' who did his bidding at the Capitol building. Let's face it America ended up with the playground bully in charge.