Arguing across partisan divides is never easy, but you may have noticed that it now seems impossible. Shared facts - the basis of any rational discussion - no longer exist; basic existential claims like "Trump said one thing on Tuesday and a different thing on Wednesday" are as ineffective as complex arguments about moral theory. Literally nothing you can say seems to penetrate; no words seem to make any impact on your opponent's position or fervor.
The reason is because Republicans are now post-language. Words have become merely a sequence of sounds that one uses to establish dominance; they no longer have semantic content. When a gorilla bangs its chest and roars, the only intended meaning is a display of power and a demand for submission. If you were to ask the gorilla what ideas his roar was trying to convey, he would be mystified at your cluelessness.
If this surprises you, it shouldn't. This is the natural and inevitable destination of fascism, as made clear by history and the novel 1984. The raw exercise of power does not depend on ideas; indeed, it can only be challenged by ideas.
There are only two ways to achieve a goal: force and reason. And reason is merely the special application of force by an entity upon itself. To reason with a man is to convince him to use the power at his disposal to constrain himself, rather than to compel another.
Republicans, unable to convince a majority of other people that their goals are desirable, have given up on reason. They now operate solely in the realm of force. Trump has made this clear many times; perhaps his most obvious tell was at a recent rally when smugly pointed out that he, and no one else, occupied the White House. Power, presented as its own justification.
This is why you cannot argue with a Republican. All you can do is deploy word-sounds that would make you dominant over them, to be countered by their word-sounds that reclaim dominance over you. To do anything else - to consider the concepts you advance - would be to deal in reason, and they have already conceded that is a losing battle.
This is why no Trump supporter cares about Trump's contradictions, or policy failures, or treasonous acts. Whenever you mention those, they are merely plays at dominance, to be refuted by displays of their side's power. Trump's position as head of the government is the only message they can hear.
The good news is, without power, the Republican project collapses. There will be no armed revolution on the part of the Right if their currently ongoing violent coup fails. They are bullies, and like all bullies, cowards once deprived of power. Without power, they have no organizing principle, and no language to communicate with each other.
The bad news is that the desire, no, the psychological need for racial and gender superiority, is so strong in so many of our citizens that it seems altogether unlikely that democracy can survive. A house divided cannot stand, and 40% of our citizens want the illusion of white male supremacy more than they want reality.
The defeat of Trump in November is necessary to the survival of the republic; but not at all sufficient.