I can't stress this enough: The current left wing is not ideological, it is religious. They are religious fanatics sure that they are on the road to Utopia. And you are Evil with a capital E if you get in their way.
They are quacks. Don't try to reason with them. Don't try to embarrass them by pointing out their hypocrisies. They don't care. It isn't ideological. It's religious. When you talk to a left winger, it is the same as if you are talking to a flagellant. Logic's not gonna do it, Hoss.
You deal with a quack by mocking them. Do not take them seriously.Let them talk, laugh, roll your eyes, and then continue as if they had said nothing. If they get mad, laugh. Treat them as you would a girl. Agree and amplify. "You're a racist" Say Ok and then wink at their girlfriend (unless she isn't hot, which she probably won't be).