Avoid Engaging Directly with the Person You are Debating
This tactic is for when you don't think the person is worthy of direct one on one engagement as they will never change their mind. Talk to everyone reading the post and not the author which is beneath you. So don't @ them or use their name or say the word 'you' such as “you're wrong”. Instead, simply debunk whatever they posted and in furtherance you can refer to the person as part of a group with phrases like “Right-wingers actually believe this stuff” and you could even follow with something like 'if you vote for Republicans you are supporting stuff like this'. 'People actually believe this stuff.' 'This is wrong and unfortunately right-wing media is so effective at getting so many to believe and spread their lies'
If someone is posting a bunch of irrational stuff it is going to be really hard to reason with them. So instead, engage with everyone else who reads the post.
It is also possible that a person you are debating is trolling and doesn't actually believe what they are writing. It is so difficult to determine if right-wing posts are by trolls these days as so many people genuinely believe crazy stuff like the seditious Qanon conspiracy theorist who got shot and killed at the Capitol. But since so many right-wingers believe the crazy stuff, you don't have to worry about falling for a troll as some people may believe it if left unchecked. Anyways, if you don't directly engage with the person but to the readers of the post instead then you did not fall for the troll.