You don’t need a phd to understand what is going on. Trumpism is a populist movement, just as Bernie Sanders was on the left. The reason is because neither political party is helping the vast majority of the American people. Instead they are wasting taxpayer money on foreign wars, and things that will not benefit the average person. The one very effective way to fight populism is through identity politics. Thus in order to keep the people divided they use identity politics. Populism is everywhere in the world and isn’t an American political thing. The French too have been protesting for very similar reasons.