English historian Peter Heather controversially argued that Rome was ultimately overcome by illegal immigration. Heather accepted the academic analysis that the Huns on the Pontic Steppe in the late 4th century set these migrations in motion.
However, according to Heather, the assumption that the barbarians were then peacefully absorbed Rome “smells more of wishful thinking than likely reality.”
Rome had always been an inclusive society that welcomed immigrants. Immigrants were given employment in the Roman army, but were welcome only if they assimilated. But Rome still fell.
What makes anyone think that the United States and Europe can absorb violent non-assimilating immigrants from all over the world with the result not ultimately collapsing 21st Century civilization? The architects of this collapse know full well what they are doing.