Foreign science grads are what is driving the US as a leader in R&D. Look at the post-docs at labs in MIT, look at the US Nobel prize winners - the majority of them are immigrants
If companies are limited to domestic scientists then they'll quite happily move their R&D departments to countries with more relaxed immigration laws. Foreign universities will happily take the best researchers from around the world that are denied work in the US.
We're seeing this in the UK from the Brexit fallout. We were getting the brightest from around Europe working in our research labs. Now that we're going to make it more difficult for them they're probably going to go elsewhere.
If companies are limited to domestic scientists then they'll quite happily move their R&D departments to countries with more relaxed immigration laws. Foreign universities will happily take the best researchers from around the world that are denied work in the US.
We're seeing this in the UK from the Brexit fallout. We were getting the brightest from around Europe working in our research labs. Now that we're going to make it more difficult for them they're probably going to go elsewhere.