“Many will simply leave the US when that happens.”
I would view history as a guide on this.
Even if the central government falls (as history says it must eventually) that does not mean that people flee the former empire.
It would probably revert to local warlords—with some being vicious and cruel and others more enlightened in the treatment of their subjects.
One benefit—the lies about “democracy” would be over—it would be a time for truth telling.
I’ve already read posts across the net that are American citizens already expatriated, in process or planning to leave.
However, I wasn’t clear: I expect the invading parasites to leave. Some will stay to participate in the sack.