From my perspective there’s four broad scenarios that might occur.

The first one assumes

1. midterm elections are legitimate
2. the democrats sweep
3. they then immediately and aggressively use that power to start unfucking everything, prosecute the fascists, expand and stack the Supreme Court, and majorly overhaul the parts of the system that allowed Trump and his backers to gain power in the first place. If that happens I will be shocked and happy to be proven wrong.

The second assumes the first two, but in place of 3 they continue the pattern established by the Biden admin of milquetoast appeasement and “nothing will fundamentally change”. That will just lead to more growing frustration with the democrats and disillusionment with the American system. If trumps alive in 28 he will refuse to step down and no one will stop him, if he croaks and JD takes office hes going to continue degrade the US because he’s Peter Theils puppet even more than Trump is and Theil wants the Fed to collapse so he can be a god king in a corporate city state(for more on that look into Curtis Yarvin and “the dark enlightenment”)

The final two are much more simple and in my opinion more likely than either of the aforementioned. Assuming the elections are not legitimate and it’s a manufactured red wave there’s only two ways that goes, the American electorate decides it’s unacceptable and rises up to stop it, or we just sit back and do nothing.

The worst and best scenarios are the only ones where I think the US stays together. A revolution would require negotiations for where things go from there and to your point California could easily go their own way and be fine, Texas might just want to even if it’s not as good a plan. And there’s also so many factions within the maga that want to carve things up for either religious, racist, or corporate/profit reasons.

I hope I’m just a cynical pessimist but I don’t have much faith in the existence of the United States federal government without major reforms for much longer