A fair and complex question. Also perhaps worthy of it's own thread. I do not see this is a realistic thing to happen soon, in this presidential term or maybe in this decade. Things will have to get much worse in this country but they are on track to. So maybe, as things get worse, people in the military will stand up. And I think it would be the best hope to fix things. I am envisioning a coup around the level of the colonels, no higher, this is historically where many or most coups actually start, as the generals are too invested in politics and the deep state as I've called it and the military-industrial-intelligence-congressional-oedipal complex, whereas the colonels and under are more strictly involved with military matters although of course it is still political. The average soldier, though, and the average officer, at least in the lower echelons, share the values of the American people because they are, of course, American people (and one might think they're overwhelmingly conservative, which actually isn't true, there was recently a poll done about this that I read somewhere), and many of them hate the system as it is, resent the spooks and the deep state, resent what's happening to their families back home, the government-by-big-banks and so forth. Now, and this might also be worth it's own thread, due to the structure of the American military, it'd be very, very hard to pull off a coup because the country is so large, the military so dispersed and complex in it's structure, etc.
It's virtually coup-proof, in terms of traditional coups as we see often in Latin America and other places, of course, so there would have to be some sort of organization and getting that many junior officers (in particular) to participate in the plot, which would have to involve at the very least seizing Washington DC, New York, headquarters of various agencies (especially FBI, CIA, NSA) and very importantly the various Internet hubs and data centers, with tanks and boots on the ground and everything; this just imagining in the East coast, on the West coast various media centers, Silicon Valley company headquarters (Google and Amazon in particular); as difficult as this would be, then significant manpower and even a nuclear equipped something or two as an absolute "don't tread on me"; no doubt never to be used, but as madman-theory-deterrent type thing. In certain parts of the country many citizens might join as armed militia along with the coup and ally themselves to hold down state capitals, etc. State governors and national guard units could defect. Almost as a secessionary movement in a sense but with an aim of taking the whole country, or, perhaps, splitting it up into different parts, which already exist, but splitting it up more formallly. Law enforcement could be an important ally especially if the messaging is right in terms of helping them defend against the increasing degeneracy and chaos. So hopefully things will be mostly bloodless.
Now, it would be difficult to get the American military to make war on itself, or to shoot American citizens especially their fellow soldiers. They would not fight a new Civil War. So at this might probably wind up in a sort of stalemate situation where then negotiations would proceed in forming a new government. A new Constitution even. Secession for some states, splitting the U.S. up into the several different countries it already is. Temporary military rule, trials for the wrongdoers, etc., then evolution into a better government. This is a fantasy right now. But perhaps in a generation, perhaps by some kind of new (or not so new, just newly applied) digital communications among the military for recruitment and organization, in the context of worse and worse economic and social conditions in the U.S., it just might be able to happen. It is a far out hope. But it is a hope. And it is I think our best hope to fix the nation.