The point of all this is that racism and ignorance have a long pedigree in the White House. Race is a big deal in the USA - starting at the top, and going down from there.
It is indeed. but what I think is unusual is that I don't think Trump is even spectacularly racist, personally. I think he's an equal-opportunity bully who will play any card in his hand against whoever he sees as his opponent. I think it's quite telling that he is among the few presidents in this century who has not had a heard-in-private racist quote attributed to him (Clinton had some awful ones - ugh)
The things he's said, against women, against minorities, against disabled people, etc., have all generally been
quite public (other than the pussy-grabbing quote which again was about his own ego, wanting to impress the guys he was with, despite the fact that his quote doesn't even make sense)
I think Trump has made it quite clear that the people he goes after are people he feels have slighted him personally, or those he thinks he can get his supporters to rally with him against.
He's too self-absorbed to find the energy to actively, continuously hate anyone unless it's someone who has spoken ill of him or who might harm his brand. And then once he feels satisfied that he's gotten the better of them, he forgets all about it. It's very telling that so many people - Megyn Kelly, Al Gore, Obama, Enrique Peña Nieto, etc, all once sworn enemies of his whom he pursued with violent vitriol, all come out of brief meetings with him looking slightly bemused and beside themselves, ready to work with / negotiate with him, or at least willing to forgive a little. I think this speaks to the fact that he really doesn't believe the things he is saying at the time. If you are willing to do business with him, he is willing to make you feel like the king of the world (this is true narcissistic personality disorder behavior)
The fact that he doesn't really mean it - all of the nasty things he says - doesn't make him any less dangerous - in fact it makes him more so. He is the epitome of a schoolyard bully who will find the (perceived) weak spot in anyone without a second thought to the repercussions of that bullying - that others with less power than him will continue the chants and harassment of his victims long after he's forgotten what he even said - that he will have so many followers emulate his style and cruelty because they saw it "work" for him.
It's also a form of "negging." He talks trash about someone who never would have given him a second thought otherwise, then he gets on their radar, and then he gets to win them over by suddenly showing them a little bit of decency / kindness.