> And that worked out excellently for the US.

That worked out excellently for the US at a time when the US was more or less empty and the west had to be settled and the government was going out of its way to encourage people to come and tame the land. Unsurprisingly, centuries later the situation has changed significantly and it's now in our best interest to be slightly more selective and organized when it comes to bringing people into the country.

Regulating immigration is only going to get more important as more Americans are forced to move due to climate change/water shortages/desertification (already starting, about to get much much worse: https://www.forbes.com/home-improvement/features/americans-m...) and as the country does its part to help accommodate the 1 billion climate refugees who won't be looking to immigrate because they want more money or better jobs, but because they literally won't have homes to go back to.

We need to be preparing ourselves for some hard times, being much more careful about the number of people we let in, giving more thought about where we're putting them all, and making sure that we're enabling them to be successful after their arrival. Regulating immigration is important. It can be done without being as evil and heartless as possible. It's important that we don't let the cruelty of the current administration cause a backlash which leads us away from common sense.

> It's important that we don't let the cruelty of the current administration cause a backlash which leads us away from common sense.

Unfortunately, that reaction is practically axiomatic. It's tough to tell progressives to temper their responses to the abject cruelty and wantonness of this administration when the administration itself has shown no restraint whatsoever. If they would stop talking about alligators eating detainees, there's a chance of having a rational adult conversation around common ground on immigration.

Much of the west is still empty. The idea that this country is full is manufactured scarcity from restrictive zoning laws that did not exist when this country grew hand over fist just fine off immigrant labor in the 1910s.