the collapseniks imagine, after their collapse has taken place, that there will exist a "United States'' with the same borders as the current one, albeit with a wall round it.

Which misses a fundamental point.

That nations are held together with the threads of energy that built them,

ie the roads railways and airlines radiating out from the capital.---washington.

But it will be energy collapse that makes those threads unravel

no matter who is in command in Washington, if command of say. Texas, cannot be continued because no means of physical communication exists, then Texas will eventually secede from the union, along with many other regions, because the means to prevent it will not exist.

So the USA will devolve into six or seven autonomous regions., and in no time they will be fighting each other.

So downsizing will come--despite denial of it.

https://end-of-more.medium.com/you-wont-like-downsizing-975571bc846d