If it is someone you care about try to keep the lines of communication open. Assure him or her that you’re always available to talk to or ask questions. But insist on two rules: insist that they be honest, and insist that they not be insulting. Despite their protests, it is not hypocritical for you to set the standards or the ground rules.
If there is a reasonable person hiding in there you can bring them out and become a critical thinker.
If they are “progressives” they will be incapable of following those two basic rules.
I make it clear to my relatives, that I love them, but I will not talk politics, you aren’t going to change my mind, and I’m not going to change yours’, so let’s just leave it at that.