But we've never expelled immigrants en-masse for not****imilating into American society!
Uh..... yes we have. The Palmer Raids and what was called "Red Summer."
Post WWI a huge number of people flooded into America. Many of them came with no intention of****imilating into America; they instead brought views favorable to Communism, socialism and even anarchy. A material percentage engaged in plunder and other serious criminal acts; fraud, theft and more.
The government rounded up a large number of them, put them on ships and sent them back to Europe. Where parents had come here and spat out kids, but were involved in radical activity (e.g. communist advocacy and similar) the parents were deported and effectively forced to take the kids with them.
Then a few years later, in 1924, Congress passed the Immigration Act of that same year. National origin quotas were put into place and enforced. Many nations saw their quota drop by 90% or more. America was declared for Americans first and those who refused to****imilate, rather believing they could bring their social values to America and change neighborhoods and cities to their preferences, had their dicks slammed in the door. Immigration from Asian nations was entirely prohibited.
It was called "xenophobic" but..... it worked.