The other thing I've found is that in those cases, the toxicity of their reaction will (at least slightly) move the opinions of at least some people watching th

The other thing I've found is that in those cases, the toxicity of their reaction will (at least slightly) move the opinions of at least some people watching the conversation. So I tend to cut bait and move on at the point where it starts to upset me rather than the point at which the conversation itself is obviously futile. However my tolerance before I start to actually be upset is relatively high - most people would be significantly better served by bailing out earlier and I've seen too many people burning out of having such conversations entirely because of not doing that and I miss their perspective so would prefer they set boundaries that work for them. (in case you can't tell, I like being covering fire and it very definitely earns me more friends I am glad to have than enemies I would have preferred not to have)