I'd like to ask, without the political sniping, what is the purpose of immigration in today's world? Besides the obvious point of diversity. When we have so much poverty, unemployment, lack of affordable housing, massive meat and poultry farming to feed everyone, high cost Medicaid and other social services, I honestly don't see why we just allow so many to immigrate here. It doesn't matter where they are from.
When is this country 'full'?
Well... actually that's not entirely true. America's very affordable to live in, for a developed nation. Partly because we have so much space, and we aren't actually very densely populated. We also have a much lower unemployment rate than, say, Europe. And on top of that, we also make a lot more food than necessary. A lot of that gets exported, or wasted.
So, there's not really any issue with feeding, employing, and housing people, per se.
We also have a very hard-working immigrant culture. We almost have to, with how hard it really is to immigrate to America. For the most part, we're not paying these people to sit around doing nothing. They're working their asses off and paying taxes. Most immigrants in America actually work more than the natives do.
On top of that, America also has much better success integrating immigrants than most other developed nations do, in part due to the way we handle development. Outlying areas that immigrants can afford (immigrating is insanely expensive and even if you make decent money, you're gonna be tapped out when you land) are much better supported, in our more suburban and rural sort of culture, than they are in highly dense countries. That's why we have less alienation and consequently less radicalization of our immigrants than Europe does.
Immigration has always been a major part of keeping America innovative and on its toes. As much as 50% of our entrepreneurship comes from immigrants. Indeed, encouraging innovative people to move to America is part of what makes it... well, America.
I just don't see the crisis everyone is so worried about. American immigrants are actually uniquely effective and involved in our culture, in a lot of ways.
Obviously we have a lot of problems right now. But frankly, so does the rest of the world, and none of those problems are due to immigration.