In other words, we have plenty of potential workers, more than our developing high-tech world may require. (What is true is that while there are no “jobs Americans won’t do,” there are wages Americans won’t work for. Ending immigration and thus limiting worker supply would increase those wages.)
Now, this said, there are many reasons to end immigration completely, ranging from the cultural to the demographic to the electoral. But I’ll exercise discipline and keep the focus here narrow, on population level and overcrowding’s effects.
As to this, do we really need more strains on resources (e.g., water) and more crowded schools, hospitals and highways? Do you take your morning commute and, while battling traffic with the white knuckles strangling the steering wheel, think “Gee, what would really make this trip more interesting is 35 percent more cars on the road”? And as the aforementioned statistics inform, we’ve added to the U.S. in just the past three years a foreign population (5.3 million) greater than that of each of a majority of our states (27). Is this wise?
Founding Father Thomas Jefferson certainly didn’t think so. “When we get piled upon one another in large cities, as in Europe,” goes a famous paraphrase of his thoughts, “we shall become as corrupt as Europe.”
Population density’s implications should be seriously pondered, too. Just consider, as a cautionary tale, ethologist John Calhoun’s 1968 to ’72 mouse experiments. To be brief, Calhoun investigated the effects of overpopulation by allowing eight mice to breed in an area of limited space while providing them all the food and water they needed. As the population density grew high, violence, miscarriages, poor parenting (ignoring of offspring), narcissistic behavior and, eventually, demographic decline and population collapse resulted. They became “piled upon one another”--and became “corrupt.”
Now, to be fair, the above is a bit like those old studies in which, investigating the effects of artificial sweetener saccharine, researchers would feed lab rats doses that were, proportionately, hundreds of times greater than what any human would consume.