I think I might have come across a great idea.
I was thinking about what I might say in a debate against a leftist if they were to accuse me of being a sexist (racist, nazi, etc. will also apply to this but I was thinking about the accusation of sexist in particular) and I found that my response was derisive and not quite mocking. When I realized this, I began to think about how they and anyone that was listening would respond to this, from the point of view that my audience was generally left-wing. Than it hit me: this is how we could win!
Hopefully some of you guys have heard of The Distributist's "Magical Words", words such as racist, sexist, nazi, xenophobe, etc. These are word traps: if you say that you are not a nazi, they can simply say, "That's what a nazi would say!", and if you embrace the identity, no one will listen to you and you will be discarded and removed from the argument. The way we can get around this trap is to simply avoid it. It's all rather simple. All you have to do is treat their accusation with derision and say that they are lying. Also, make sure you throw in an insult in there. It doesn't have to be a good one, and make sure you don't insult them too much. Your goal is not to get in an argument of verbal abuse. In this manner, you have sprung their trap without stepping in it. They can respond in four ways: by doubling down and asking you to 'prove' that you are not a nazi and/or saying that you are lying, claiming that they are not a liar, insulting you in return, or asking why you have insulted them. It should be pretty clear that most of these outcomes are an immediate victory for you, or at least give you the upper hand.
If they double down and repeat that you are a nazi, they are essentially calling you a liar in return. The left has tried to imbue all of their magical words with the inbuilt implication that the person you are accusing is a liar, however it is not directly recognized, and the far more direct meaning of 'liar' will stick out much more than the implications of their accusation. So, you double down in return. Continue to ask why they are lying about you, and why they need proof. Your goal from here is to deride the very notion that they need 'proof' that you are not a nazi. They might also directly use the word 'liar' themselves, which is a stronger argument for them to make, however is easily countered by calling them stupid or insane for lying about you and than lying again accusing you of lying. In both paths, you should make the whole idea that you are a 'secret nazi' completely laughable, and make your opponent look like a fool for suggesting so. They might also directly use the word 'liar' themselves, which is a stronger argument for them to make, however is easily countered by calling them stupid or insane for lying about you and than lying again accusing you of lying. In both paths, you should make the whole idea that you are a 'secret nazi' completely laughable, and make your opponent look like a fool for suggesting so.
The next option is to claim that they are not a liar. This gives you an opening: if they are not lying, they must be an idiot or insane to accuse you of something like this. Laugh at and deride them. After this point, they will realize it is not working and transfer to another one of these responses.
The third option is for them to insult you in return. While it might seem like your goal is to get into a flame war based on these tactics, your actual goal is to deride all accusations/emotional arguments that your opponent makes. You let them set their trap, and if you spring it without getting yourself caught, they will end up embarrassing themselves in front of their audience and looking like an illogical fool. Therefore, if any of these responses eventually lead to an insult war, your goal is to stop it as soon as possible. Make it clear that you are the logical one, they are the one who insulted you first after all. If you treat their accusation like an insult and steadily escalate the language, you make it clear that you are not the one who started it, nor did you freak out. If you bring the debate back under control and into civilized territory after this, it will further you towards your goal by making you look much more mature that your opponent.