This is literally what he sent me:
You're offspring will reap the demise off your ignorance, be it slavery or another form of retribution. You're unwillingness to acknowledge injustice will bring the wrath of vengeful and irrational beings, seeking reparations in blood. I sought to enlighten you to a reality you were not privy to through the stories of people who lived those hardships. Those "criminals", as you call them, will come to eternally rob you and your next of kin of light... I wish the best for you.
Really fucked up stuff, this was a good friend of mine. What happened to people?
Sorry this happened to you. I had a friend of 20 years pull something similar on me. Think of it as if they’ve been brainwashed by a religious cult, because that is basically what this is. The leftists use the exact same brainwashing techniques that cults use.
You can’t TELL someone who is under cult mind control that they’re wrong. They’ve been indoctrinated to dig in their heels when someone directly tells them that they’re wrong.
At most, you can use the Socratic method to ask them questions to make them think about the illogical aspects of their views.
However in a lot of cases you’re probably better off just moving on and finding new friends who share your values. I still talk to my old friend who called me a racist, but it will never be the same.