I've been dealing with this for a while now. Family kicked me out of the house for supporting Bernie Sanders at one point. It sucks, because I love them very much, but they're Racist with a capital R and die-hard republicans who worship drumpf. Every time we talked they would bait me with their BS, and even when we're NOT talking about politics, it seems every gap in conversation is punctuated with all the vile things they're trying not to say.
My therapist had some great advice. Said that if I value a relationship with them, then the price for having that relationship is never discussing politics.
I'm willing to pay that price, so I told them not to bring it up anymore, and I'll do the same. It's working for the most part, though that doesn't stop other issues from coming up. But hey, that's life! Wouldn't be relatives if they didn't frustrate you endlessly, I guess?