In theory, there are no Americans available in those highest levels of skill to be forced out. I’d be interested to see studies that tried to actually assess that.
Anecdotally, lower margin industries (think manufacturing sector) employ almost exclusively immigrant tech workers because the salaries are too low to retain any but the least skilled US coders.
The naive interpretation is that these companies would pay higher wages without access to H1B workers.
Studies like TFA suggest that is not actually true. Companies in all sectors are constrained by the availability of skilled labor and to some extent are paying what they can afford.
Reducing the number of H1B visas would likely hurt employers to the extent that their workers would suffer. It is not sensible to pretend that all of those jobs would still exist if you cut the H1B program.
