It is not just about the past. A king is only as powerful as his subjects are loyal. Trump continues to hold sway because people have remained trusting of him and are willing to go along with him. They don't have to, but they choose to.
Right, and a constitution that allows that to even happen has also failed. The American system was supposed to be somewhat elitist and prevent wild populism. So it didn't do that. It failed. Perhaps related to the overly permissive definition of speech in the US and subsequent extreme partisanship. Or perhaps presidential systems actually are quite shit in comparison to parliamentary ones. Anyway, obviously the country is very, very sick at the moment.
First past the post voting is one critical root cause. It prevents coalition building and compromise. I think that's a much bigger smoking gun than presidential vs parliamentary.
I think this is too simple. The right wing was on the rise in most of the rest of the developed world too, until Trump scared everyone straight. What factors led people to think this brand of politics is a good way forward? Simple media? Social media? Propaganda? Foreign propaganda?
Personally I think it's a mix, but inequality is a big factor. Quoting Roosevelt:
"But I venture the challenging statement that if American democracy ceases to move forward as a living force, seeking day and night by peaceful means to better the lot of our citizens, then Fascism and Communism, aided, unconsciously perhaps, by old-line Tory Republicanism, will grow in strength in our land."
