I guess I would engage you on this point. When you speak of "reaping and sowing", even in the context of only Republican's it presupposes that their mindset is wholly their choice. I think it is striking that Trump's base is uneducated white men and it makes complete sense. This group is usually poor and feels hopeless in their situation. One thing they can have pride in and hang their hat on it the concept of American exceptionalism, and so it is no surprise that the entire Trump platform revolves around callbacks to this and how the other side is threatening it. They are not helped by the "history" taught in large parts of this country.
As an example, I was watching a video the other day of a young man watching Kenji by Fort Minor. He was blown away by the concept of internment camps and kept asking what book this was based on. This and slavery, and the trail of tears and a myriad of other American atrocities are barely covered, if at all. Even in California the internment camps were barely covered in my AP US History class. I was lucky that my dad's Friend was born in Manzanar and took us there as kids to explain what this place was and how his family was affected by it.
Anyways, all of this results in a large group of people who believe in a saintly, sanitized, fictional view of America that they were taught. Any attack on this vision is met with hostility because they have no reference for America ever being the bad guy. So it is not surprising that can be herded like sheep. I am not trying to excuse the mindset or actions of these people just to frame how I think we got into this place.