At one point, somehow the topic of abortion came up while my father was visiting me from the other side of the country. I basically said that I have zero tolerance for anti-choice sentiment and he kept trying to argue with me about it, and I told him eventually that that sort of talk wasn't welcome in my house.

He tried to "win" me over by saying that I wouldn't be here if my parents believed in abortion (my mother is actually pro-choice just would never abort herself, but I didn't get into that). I told him that would be fine. I would never have even known that I didn't exist.

I know that is the common response, but it's true, and it also actually shut him up. That and I think he believed me when I told him that he would not be welcome back in my house if he continued that kind of talk.