I don't know. I agree with you on almost all the points, and he obviously is a self-centered narcissist who only like himself. However, I am not really convinced about the racism explanation. While it may play a role for some people, I would venture to say it's not the explanation for the majority.

I know several relatively well-off rabid Trump supporters, and I wouldn't call them racist. However, the common denominator there is a tendency to like "strong" leaders and conspiratorial thinking. It's the same reason why guys like Putin, Orban, or Erdogan are popular among certain sections of their own populations.

Besides, Trump has polled well among the Hispanic population, and there also a pretty large group of black supporters (especially among men).