It can't just be about the fascism.
It can't just be about the fear and the violence, and it definitely can't just be about the bigotry. For far too many people, those just aren't deal-breakers.
It has to be made clear that these people are crooks and incompetents, that they don't care about America's future, and that they're unfit to lead in a crisis. Bang on that narrative again and again and again.
Because sooner or later, and I hope to whatever is listening that this doesn't happen, someone is going to hand Trump his 9/11 moment. He's been trying to trigger his own with no success, but really he just needs to wait. Ideally it'll be a freshly enraged Iran, but anything will do. Suddenly America will be in crisis, with no time for division or argument, and the best thing for everyone will be to get with the program and do as they're told.
Every Republican who might have mildly disagreed with Trump, most of the independents, and no small number of Democrats, all the military and business leaders, the pundits and influencers, will eagerly fall in line, many with audible sighs of relief. Dissent only helps the enemy, after all, and what are a few strangers you never really cared about in the first place when the nation's safety is on the line?
The only way to counter that that might work, especially if you were already saying it loudly before The Event, is to make clear that the current leaders are the ones to blame for the crisis and/or can't be depended upon to see America through it. Talk about how they're mismanaging the country's security and defense infrastructure. Talk about their "fire and ask questions later" approach to the civil service. Bring up their cowardice and indecision. Hammer on every documented event that proves they don't know, and mostly don't care to know, what the hell they're doing. Ask people, "How safe do you feel?" Build the case that these are not the strong leaders America needs and they never will be.
And keep talking about the fascism, the fear, the violence, and the bigotry, too.