Friend starting to bring up politics for no reason.

I have this friend, he's one of my oldest friends and for whatever reason, in the last few years, randomly he'll bring a conversation back to politics and start talking about people who aren't on his political side like theyre crazy. Not knowing I'm completely on the other side I just refuse to talk about politics with people.

I'm pretty good at changing the subject to something adjacent and then just getting past it but idk. He more or less just told me he is losing friends because of his supporting of trump and I was so tempted to be like " man we're canadian.."