I think at that point they use alt-media sources to paint the democratic victor as the source, directly or indirectly, of the problem, followed by getting rid of said problem in the name of protecting the republic, along with as many other high ranking democrats as they can "reasonably" draw into the conspiracy.
it's clear Americans don't care now and the vast majority of them will believe whatever he says at this point, at least among those who vote for him. If he's feeling strong enough to go that far, and again this is all hypothetical, it's fair to say they will believe him when he says the democrats not only cheated again but are by force attempting to take the presidency. Until "proper" elections could be held, it would remain in his control.
The primary thing stopping Trump from achieving something like this is his age, which I've mentioned before. I doubt this all comes to fruition because he's too old, but in this highly theoretical situation, his successor would be much younger, would have already won the Republican primaries and thus, would already have a large cons uency of supporters. The writing could already be on the wall, tbh.
At this point, it's easy to understand why the Germans let the Nazis take over and do all their crazy . People simply don't care as long as we have our bread and circuses. Our holdout is literally hoping Trump really does love his country and/or there's not enough momentum (like you said) in the federal government, including the SCOTUS, to actually achieve these ends.