The only thing that will stop this is a string of election defeats. That will cause them to shift strategy.
If they win, then US "democracy" will become no better than Russia's.
Not sure about that. From over here, the institutions of US democracy look fairly robust, so far anyway. The problem may be the electorate itself - Biden comfortably saw off Trump in the end, but that can’t hide the fact that many millions of ordinary Americans voted, in Trump, for a man who appears to have none of the hallmarks of statesman, but all those of a would-be tyrant.
I worry more for the future of democracy in Europe personally. In the U.K. we have no written constitution to protect us when the right start ignoring democratic conventions - as we saw with Cummings and the proroguing of Parliament.
That said, there are signs in the U.K. at least, that the tide may be turning against right wing populism; Boris Johnson backed the wrong horse over England’s football players taking the knee, and I hope it costs him.