Ask a question: why does it matter who I choose?
Conservative ideology is inextricably linked to the brain’s disgust response. As in, people who demonstrate a stronger disgust response in the brain overwhelmingly correlate to conservative politics. It’s visible on an MRI.
Because of this, I can hypothesize that the only way to remove conservative ideology from a person is to disable the disgust response to the thing in question. In most cases this happens when someone they love turns out to also be the thing that disgusts them. This causes a conflict, and the person must actively decide to retain disgust or diffuse it. However, “coming out” is dangerous, because you can never be sure if the person will be willing to confront their own ideas, which is difficult, or eliminate a person they care for from their life. Therefore the only way is to force introspection. Make them consider putting their disgust into words, because it has no legitimacy.
“I don’t like gays because they’re gross.”
And when all they can say is “Because they are…” their disgust is shown to be irrational.
And so I say, ask questions. “Why does it matter to you? Why is that important? How could you ask that? What’s wrong with you?”
And so on.