Yes I understand that the finalization of NAFTA was years later but the seed of NAFTA was the immigration program the same players where lobbying for both and saw them as complementary legislation in a package of legislation they wanted passed. It did not reduce the cost of farming for my family because it was a family farm, any labor cost killed the economies of scale as we did not have the volume to compete. The reduction of return to noncompetitive levels started with the immigration visas and was completed with NAFTA, then the conglomerates turned around and picked up most of the viable land from the farmers NAFTA killed and then petitioned for more immigration reform, to reopen those combined tracts. As I said, I have no skin in the game, I did not want to be a farmer, but that is how it works and that is how it is done. You can argue that it has an overall net positive effect because it reduced the cost of goods and that is one way to look at it. But it came at the cost of consolidation a good deal of middle class land wealth into the hands of a few mega-corps.
The visas in question made it easy to legally hire foreign (mostly Mexican, I’d guess) agricultural workers. That would have reduced the cost of farming your family homestead.
Canceling the visas presumably encouraged many of those workers to accept lower wages to work farms in Mexico. The old visa program was effectively a subsidy for US farms; ending it created more competition for US farms. Arguably, it also made NAFTA more likely to happen, since it moved agricultural production from the US to Mexico, and people have to eat.
Suspending the H-1B and green card programs will have the same long term effect on the US tech industry.