There can be a problem, though, with very uneven types of protectionism. For instance, suppose both apples and oranges are both subjected to very high tariffs.

There can be a problem, though, with very uneven types of protectionism. For instance, suppose both apples and oranges are both subjected to very high tariffs. Then, you remove all tariffs from oranges, but leave them high on apples. you should expect domestic production to shift to apples and foreign production to shift to oranges, to the extent possible. I can see how you would feel that creating more work visas would lead to a freer market. However, if these visas are heavily concentrated in STEM fields, this may end up producing a very distorted market that deters US citizens from pursuing degrees in this field. One of the provisions of the immigration bill is to grant green cards to graduates of US-based STEM programs at the MS or PhD leve. Rather than a more general liberalization of immigration, that's just the sort of highly specific, targeted program that can produce severe market distortions. Many of the people who object to these visas actually support more general liberalization of immigration - they just object to visa programs that are based on the notion that we need to use immigration specifically to increase the size of the STEM workforce. This is because they believe, as this article suggests, there is no shortage of STEM workers.