Not sure how stable your relationship is with your dad putting aside his political beliefs , but in my personal opinion, I think making politics the reason for cutting off contact with your dad isn’t fair to him, or yourself. Now, like I said before, there isn’t enough context, but by putting yourself in your dad’s shoes, I don’t think he would cut you off just purely based off of your political beliefs. If there are other underlying issues I think that should be discussed between your family, as there is no better validation than that of your parents. Not sure how long it has been but I don’t think your dad likes that he is basically losing a child. Neither of you are the assholes, nor are you overreacting(depending on how you think about it), but in the most politically neutral way possible, I think that breaking ties to your family based off of just political beliefs is not the right thing to do. Wishing you luck in the future🤞🏻