He equivocates actively opposing racist violence as being the same as racist violence. He has referred to white supremacists as “fine people”, unapologetically.
One of the first times he had serious media coverage was when he was busted performing housing discrimination against blacks.
He published a full page add to advocate the death penalty for some young black men accused of murder. When they were exonerated, he refused to recant or reneg.
He was the face of a movement that suggested that because Obama is black (and has a ‘funny’ name, presumably), he must not have been born in this country and thus not fit for office, which was, is, and forever will be categorically untrue. This was one of the loudest dog-whistles for David Duke and others that Trump was the public figure they had been waiting for.
And, oh yeah, IN THE SPEECH THAT HE DECLARED HIS CANDIDACY FOR PRESIDENT, he called (the vast majority of) Mexican immigrants rapists and criminals. Later referring to immigrants of color as “animals” that are invading our country. It is also important to note that he has been at least twice been married to white immigrants, and has openly wished that Europeans would migrate here.
To name a few off the top of my head.