Agreed.

I will admit that it's draining, talking to one user who keeps moving the goal-posts.

And I will then say that I think it's their intention to drain people like me.

So I try to shrug it off and keep refuting arguments with the evidence they pretend they will be convinced by.

As one (non-American) lurker who is reading this thread to try and get a handle on just what the hell is going on over there, thank you for putting the energy in, and please don't give up.

It's clear that you are arguing in good faith and the other person who keeps moving the goalposts and demanding more proof is not, and moreover it's very enlightening to see this scenarios played out nearly identically whenever I lurk and follow a discussion between the left and right in US politics.

Unfortunately, irrational behavior applies to both sides but on different issues. I saw it first hand in terms of COVID and my liberal friends. They took the most negative possible outlook and then called you an unscientific idiot if you didn't think it was the only possible outcome. COVID has a 5% mortality rate (even when reasonable data indicated 0.5%). A vaccine is impossible (even when multiple companies said they had promising candidates). Immunity doesn't exist (even when everything except a few reports said it did). And so on.

Yes. In many cases, the only "winning" move is to say what you have to say and then step back.

You can't usually "win" the argument, just your own time.