I’m sorry you are dealing with that, it must be so deflating. How open-minded is your dad, if I may ask? My FiL is aging and experiencing some cognitive decline; though he’s been conservative most of his life, he’s only recently become immersed in hardline political rhetoric. He’s still a kind person, andhe loves his family – what has worked for me and my partner is reminding him that even though we have made decisions he may not agree with, we are are happy and (ostensibly) healthy. Connecting our situation to how his own father and grandfathers had viewed his choices and and the changes happening to society back then often helps him regain some perspective. I hope things improve, and that you and he can find some common ground.