Edit: Currently the poorest parts of the US population are stagnating at best, at a time when rates of both legal and illegal immigration are quite high. It is hard to make the argument that immigration is preventing things from getting worse.
France invited large amounts of immigrants from Africa to help rebuild so it’s not like they didn’t see immigration.
I think there are two main reasons that the poorest parts of the population are stagnating. One is poverty traps, and especially multi generational poverty traps are very hard to escape. Another is geographic location. Americans dont move as much as they used to, all around the world poorer people move to areas with more jobs and opportunity but today mostly richer people move and poorer people stay put in areas that are impoverished.
Immigrants largely don’t come with a set geography or generational poverty weighing them down which is why their kids do so well.
People coming from the Philipines, or India, or Eastern Europe, post communism from the 90s had to restart everything from scratch, including learning the language, yet over time they end up doing well.
You have this weird mentality, that all immigrants are coming rich, and from rich countries, which is the opposite from the truth.
I guarantee, that Someone in Bangladesh coming here, has had a much harder life, than the average minority living in Brooklyn or Queens.
Yet, even the obstacles, they end up doing better than the locals. So, initial conditions are not the major hamperer of success.
That doesn’t seem correct, at least not universally. Germany invited a large number of immigrant workers to deal with its labor shortage after WW2.
An argument that immigration is a net positive for the economy:
https://www.thebalance.com/how-immigration-impacts-the-econo...
Some anecdotes of small towns being saved by immigration:
https://www.houstonchronicle.com/local/gray-matters/article/...
https://www.mprnews.org/story/2019/08/15/hmong-immigrants-he...
Why would saving small towns in general be a value?
The US has desperately needed vast consolidation of small population centers and increased population density toward greater urbanization, for many decades.
One of the worst attributes of the US is its over-sprawl and weak development of public transportation. The ideal would be to eliminate thousands upon thousands of small towns, with those populations moving to far superior situations in or near cities, and for the US to stop being lazy and stupid about building out public transportation.
Saving small towns is certainly not a good argument for huge volumes of low-skill immigration at exactly the wrong time in history for that type of immigration. The US should be copying Canada and Australia, focusing primarily on high-skill immigration and dramatically reducing low-skill immigration. What the highly developed welfare states all grasp that the US still doesn't (apparently), is that the immense value in high-skill immigration, beyond the obvious, is that it brings a huge immediate net tax positive that pays for your existing population's social welfare costs, whereas low-skill labor does something closer to the exact opposite. Most low-skill labor would struggle to covers its own real social security cost over time, much less everything else. The US has a very progressive taxation system, high-skill labor foots the tax bills. High-skill labor is also vastly superior as it pertains to net healthcare costs and system subsidization. Every functional welfare state in Europe knows all of this, meanwhile the US is wandering around like an idiot in the dark bumping into walls.
Far less low-skill labor, more automation, far more high-skill labor, increased social safety net from the net tax boost of inverting the labor focus, build public transportation, greater consolidation of population centers, all linked by regional high-speed rail. We already know this model works exceptionally well and we know exactly why it works.
You're going to get pushback if you try to say "everyone needs to live in the Big City". They don't. There are other options.
Because streetcar suburbs are fine. Villages are fine. Actual towns are fine.
What's bad is strip-mall sprawl. Highways, burbclaves, and office parks. None of that is worth saving.
And some of the new "denser" development misses the point. Rows of townhomes set up in a farm off the highway with no commercial center? That's dense but bad.
New condo complexes -- private compounds with pools and such -- that take up whole city blocks? Also dense, but bad. These represent the "enclosure" (with everything that entails) of urban space.
But "small towns"? Fine -- if they're actually towns, and not just strip-mall wastelands.