At my current job around half the people are immigrants, or children of immigrants. I'm sure company wide it's similar. They don't bite.
When I went to college it was 30% asian, and they didn't bite either. There were brown kids and black kids, and many foreigners.
I don't think what makes America special is country of origin or the appearance of the people who live here. A lot of anti-immigration sentiment has undertones (or overtones) of xenophobia. This is understandable--foreigners are weird and unknown, and some parts of America are 95%+ white with few/no immigrants, or only European immigrants.
> 10 years of 10x immigration would be 100,000,000 people, so about 11 cities the size of New York of 100% new immigrants. Such masses could not possibly assimilate to any significant degree; they'd obviously form huge enclaves.
Ok, maybe 10x is too much, maybe the number should be more like 5x. This would require some sane policy from state and local governments. In the Bay Area, where I live, this would mean substantially increasing housing stock and density. It may mean other things for other localities. Maybe there are limits based on income level. But the target should be, if someone wants to come here and make a better life for themselves, they should be able to.
If someone is willing to leave their country and move to America, we can make it work and it can be a win-win for both sides.