A country whose indigenous population growth is stagnating, whose indigenous population does currently not pick up all available jobs, whose economy is 6x as big as Canada and Australia combined is choosing to turn away immigrants.
From a purely numerical standpoint, an 18T dollar economy built by 330M individuals will start to become unstable if the population starts falling and aging. This is a distinct possibility when you only invite highly educated, skilled immigrants since education negatively correlates to family sizes. Falling population will be another reason to push for more automation (see Japan) leading to wage stagnation.
America, be careful what you wish for. Read this demographic report. It's eye opening. Childbirth rates are 1.82. If you bring in Nobel prize winners, you'll get brainy people who will not beget brainy kids.
https://en.m.wikipedia.org/wiki/Demography_of_the_United_Sta...