Do you think immigrants now have different rates of assimilation than they did 100 years ago? What do you base that on? Because they don't. Immigrants have always formed ethnic groupings because that's how you stay safe. You build Chinatown or little Havana or whatever. At first these places are for 'undesirables' outside the proper good mainstream, but over generations they become a part of the fabric of society and ideas and culture percolate out. It's literally how it's always worked. For some reason there is a new wave of pampered jackboot hopefuls that think this wave of immigrants is somehow uniquely outrageously different from mainstream white culture and so must be prevented from modifying our precious sacred culture.

Pro tip: we are a culture of mutts. We draw strength from constant change. That's why we've been successful. And it's been dragging the right wing kicking and screaming the whole time. The things your great grandfather cried outrage about are now your treasured culture that must be protected.

It would be a little comical how little perspective the right wing has, if it wasn't a bit sad.