The reactionary energy and the task of Doing What Must Be Done against the left will fall to “patriot” groups - Oath Keepers, 3%, etc. with an aesthetic and aims closer to Norman Rockwell than George Rockwell.

They’ve got police/military training, discipline, recognized hierarchy and capacity to scale; many are serving in these roles and their rise represents no obvious discontinuity. They’re also well-articulated with elites of rural, resource-extraction, construction/development and supportive industries that are tied to the land and can’t threaten to pull out on capital strike.

“Rural grandees and their local forces expand their role” is exactly the reaction you’d expect to “central government falls into decline and fails to command loyalty”. (Ethno-revivalism counters foreign/imperial domination)

Seriously, though, I have no clue. There’s a LOT of ruin in a nation but it’s a finite amount and I see nothing on the horizon to stanch the bleeding or refill the account, “constrict the polity and feed the newly-outsiders to the remaining insiders” is a very real possibility in multiple directions