A big reason for the “Fall of Rome” was unchecked migration. Much of the empire lost the Culture that made it a cohesive empire. It just faded into a loose confederation of tribes squatting on territory that used to be administered from Rome.
Wondering how Haitians get to TX/MX border?
Most get visas to S. America, like Colombia, and then work their way through Panamá, Central America, Mexico....
@USBPChief
confirms many bussed to the border where they walk across the Rio Grande.