I mentioned this in another thread about Japan and populism.
People want something different than what we have, as it's not working. This alone should be cause for grave concern, because this means so long as a molotov cocktail can be tossed "because it's different than the order of things" people will in fact lean to this side. The idea of change and an upheaval to things as they are is of great desire to people who feel the society they have is not working for them. Ideally, these people should be leaning to sides and people who can specify the problem. Sanders was close, with rentierism, economic inequality, and an issue where the elite have the world and the masses have ashes. I imagine the people who went from Sanders to Trump at the very least still felt populism was better than the status quo, even if it entirely was based upon ghosts, lies, and ignoring deeper issues that are about to get several degrees worse for people.
Populism in general spawned from precarity and the deconstruction of sustainability for many, many Americans. Don't be shocked when given a choice, however bad it is to the status quo, people will pick it. Mix this with racism and "othering" of others, and it's not hard to see why even Trump had an audience. I imagine those who went from sanity to insanity here really didn't believe their lives got better under Barack Obama, and while many of us can say we have, many can also say they have not, and its level of truth is something to examine depending upon the reasons.
We should be alarmed that anybody, for any reason, would support the Orange Con Man. This speaks to a toxicity and danger that can't even be put into words.