I went last night to eat some Chinese food in Cleveland's "Asiantown" neighborhood, an area of mostly unused warehouses that's now occupied by several Chinese and Vietnamese restaurants plus what looked like a couple of Asian grocery stores. I had a meal there that probably exceeds any Chinese cooking you can find in DC proper and would count as quite good even by the standards of the more immigrant-heavy suburbs in Rockville or Northern Virginia.
It was tasty, but also a great example of how even the oft-derided "unskilled" immigrants can be job creators. The key point is that while "can make some cumin lamb or sichuan cold noodles" doesn't necessarily count as the highest-level skill in the world, it's certainly not a skill that's in abundance among the native-born population of Cleveland. To some extent the existence of this kind of restaurant may crowd out dining at other eateries in Cleveland, but mostly it serves to generate a whole new class of products—authentic Chinese cooking—that otherwise wouldn't exist in the area. That in turn serves to generate complementary employment (building trades to rehab the building, for example, or truck drivers to deliver supplies) while also bolstering the tax base of a city that's in general tended to be afflicted with population flight. To think of the city as having a fixed sum of jobs that are either "taken" by immigrants or else "left" for natives is very misleading. Most rust belt cities are at risk of a kind of downward spiral of decline, where people leave and the fact that other people have left makes it a worse place for other people to find opportunities. To the extent that foreigners can move to take advantage of the considerable benefits of living in the United States (democracy, the rule of law, free speech, etc.) by locating in places that are at risk of decline, it becomes a genuine win-win.
In terms of public policy it's a reminder that liberalizing immigration rules is probably a good idea. But also more specificially that if specific problems with immigration exist, it's better to try to address them with tailored remedies rather than blanket bans. It might be healthy to try to think of frameworks through which the flow of people who'd like to move to the United States can be specifically directed at geographical regions—your Clevelands and other cities struggling with population loss—that most need them.