My father goes off on my bf every time my bf comes over because my father don't like his politics. I've tried to stop it but my father baits my bf and then they go at it.
It sounds like you've tried to get him to stop, but he won't. Maybe it would be a good idea for your bf not to come over for awhile. I'm not sure what your father's agenda is, but politics often elicits very strong emotions. You're not going to shut it down.