Goad Conservatives into Extremist Rhetoric
If a Republican exhibits unpopular, extremist beliefs there is no changing their minds on anything. The best tactic is to instead goad them into saying more and worse stuff that blows back. This should only be used for verified social media pages where the person is known like Facebook and not anonymous sites like Reddit where people can troll.
The goal here is not to convince the person of the correct position in an argument but to instead make their friends and family who read the post feel embarrassed\angry\sad that a person they care for thinks that.
If they are reflexively refuting much of what you say, then say something that would look bad to refute and see if they bite. Then continue to say things that would look worse and worse to refute until they cross a line with consequences.
This may be enough to convince their Facebook friends on the fence to take a position on an issue and vote or chime in against the extremist. Or perhaps their response to your post is the last straw that allows someone to end a friendship or relationship with an abusive extremist or a business to avoid promoting a toxic, irrational employee or replacing them with someone better.