> It's difficult to imagine what might cause his supporters to change their options of him.

It would be helpful if people had more alternatives to vote for, not just one other party that stands for the opposite.

That's for sure, but on the other hand, in many countries the people would choose whoever doesn't normalise (and make) nazi salutes...

It's more nuanced than it might appear at first glance. I recommend watching this video, as it demonstrates the subtle complexities involved: https://www.youtube.com/watch?v=m_sVwib2rdE

The current government threatens to invade allies (well, ex allies now) and make nazi salutes, but would still win the election.

And those are only two examples out of many. You can put as much nuance as you want, fascism is fascism.

It would also help if the opposing site had better arguments than calling those they don't like nazis and fascists.

One possibility is that at least some of his "supporters" do not as much as want trump specifically but instead simply vehemently do not want what the Democrats have been doing and are willing to risk some chaos to avoid that. If that's the case (and I think it is) then the best thing that trumps opponents can do is provide real alternatives for people. Or in other words: stop attacking a large part of the population (straight white males) at every opportunity, stop trying to force radical social change, stop trying to cancel everyone with an even slightly differing opinion.