A long one but good: "America’s Struggle Towards a New Civilizational Paradigm" (Crooke). I see two disruptive changes, both from the Democrats (the Deplorables have stayed pretty much the same, and staying the same is pretty much their thing).
First, the Democrats have gone all

in for identity politics, and a particularly hardcore version of identity politics at that. After WWII Europe, human rights law was crafted with the particular concept that people shouldn't be treated badly just because of what group they happen to be born into. The Democrats

have thrown that out the window. White people are now Pure Evil simply for being white. It doesn't matter how you act, or what you believe, you are incurably racist just for being white, and racism is the worst thing possible. As you can see from the first pink section, this

doesn't go over well with the Deplorables, and we are left with the paradoxical situation that voting Trump was the profoundly anti-racist act.
Secondly, the loss by Killary in 2016, with the addition of Russiagate and various other formerly extreme right-wing tropes involving

precious bodily fluids), meant that Trump wasn't merely a politician they didn't like who beat them, but an existential threat to the country (and all this despite the fact that Trump, sadly, ended up as a completely conventional President). Killary's personal mortification of

losing to a buffoon was turned into a political doctrine. Trump's complete lack of decorum, of failing to follow the Beltway norms of civilized behavior, drove the Clintonistas mad. These two changes are huge, No compromise is possible