Former Bush speechwriter David Frum lists all sorts of things Trump does that a presidential candidate is not supposed to do — and with good reason. The worst is probably this one…
Trump is running not to be president of all Americans, but to be the clan leader of white Americans. Those white Americans who respond to his message hear his abusive comments, not as evidence of his unfitness for office, but as proof of his commitment to their tribe.
Nice of Frum to spell "clan" with a C instead of a K there. And while I'm at it, I'll link you to Jeffrey Toobin explaining how Trump doesn't understand how the Supreme Court works. He only understands that those who support Donald Trump must be rewarded and those who oppose him must be slapped down hard.