I'm estranged from a close family member because of this and many other changes in his personality over the last 15 years.
I've been clear with him, I'm ready to pick up the pieces if he is willing to go into therapy with me, together. I'll even pay for it. He tries to play this game where he wants to negotiate a third party that isn't a licensed doctor. I won't budge.
If the worst he has to go through is admitting he was wrong about a bunch of people he doesn't know, and he doesn't want to even go that far, I'm not going to pretend that I trust or respect him. I love him, but like the way you'd love a 4-year-old.
My door is always open and the offer to work these things out with a professional will always be on the table, but I will tolerate no bigotry - neither elegant nor oafish - in my life. The guy he was 15 years ago wouldn't either.
I will never give up hope that he will come around, but if not, it's because of his irrational hatred. Not mine.
There are no guides for what to do. Let your conscience be your guide.
Best of luck, OP.