I think you should respond with "that's disrespectful." Then segue into a discussion on traditional values. The thing about conservatives is they never actually live by what they claim to believe. There was a nice news segment the other day about a woman who had introduced some "anti-gender identity" legislation to the local school board. Somebody asked her if that meant teachers couldn't discuss Martha Washington because that represented a male/female heterosexual relationship. She couldn't answer of course.

However, conservatives are going to try to "win" with crude jokes long before it gets to that level. They can't defend saying "libtard" as respectful. Ask them, "I realize you don't agree with me, but can't you convey why you don't agree without resorting to disrespectful insults?" That will take the fun out of the conversation for them. Thanks for reading!