I've known it since the birther years, and had it absolutely confirmed when he said there were "very fine people" among the torch-wielding Nazis who chanted "Jews will not replace us", but all doubt had to be removed even from his blind followers after he tweeted this yesterday...
“So interesting to see ‘Progressive’ Democrat Congresswomen, who originally came from countries whose governments are a complete and total catastrophe, the worst, most corrupt and inept anywhere in the world (if they even have a functioning government at all), now loudly and viciously telling the people of the United States, the greatest and most powerful Nation on earth, how our government is to be run,” he tweeted. “Why don’t they go back and help fix the totally broken and crime infested places from which they came. Then come back and show us how it is done.”
The Congresswomen he was tweeting about were all brown-skinned. Three of them were born in America. The president is a stone-cold racist. Period. End of discussion.