Complex hegemonic superpowers seldom collapse in spectacular supernovae. They slowly wither from within, public officials crossing metaphorical Rubicon after metaphorical Rubicon (or literal, in a single case). Eventually, after a series of small norms and taboos being violated here and there–generalizing a whole group as rapists or openly disparaging a veteran or physically threatening the press or straight up repeatedly lying or offering to pay legal fees of supporters as a literal militia is forming in your name, to list some random, unrelated examples–a rupture occurs and suddenly you’re in the Roman Imperium and not the Republic. Only difference here is that Trump seems to be the Gracchi, Marius, and Caesar all in one person. Hopefully we don’t let him get to Caligula.