I'm obliged to Paul Nachman  for noticing Radio Derb's comments on Marco Rubio.
Paul correctly reproduces my remark on skilled immigration early in that segment, but adds:
A quibble on one point: Let's not admit for permanent residence/ultimate citizenship any skilled immigrants short of world-class superstars.
Actually I head in that direction myself further on:
Let's stop all skilled immigration and see which fields' salaries then begin rising fast. That would indicate a shortage; though even then, seeing those rising salaries, young Americans would flock to be educated in those fields. The case for any skilled immigration at all is highly dubious.
Radio Derb is done on the fly and I often elaborate on, modify, or fortify opinions as I go along.
If we're going to have skilled immigration, let's at least couple it to some rational economic indicators. Like Paul, though, I can't see why we need any. With 200 million people, we put men on the Moon; with 315 million we could be colonizing Mars.
The U.S.A. has all the talent it needs, if we just stop demoralizing them by depressing wages and "foreignizing " good middle-class occupations.