My wife is an astronomer, operates a 3.5 meter telescope. Last year she wanted to hire a guy from Chile but visa issues made that difficult and it didn't happen. She lost the American lady that she wanted when her boss got wind of the job offer and upped her wage, ended up with an American working in Canada (he might be wishing he'd stayed there in a few months). So this definitely could be an issue, no doubt. LOTS of foreigners at the observatory on the other telescope: three Russians, a Chinese, a French guy. I have no idea what their work visa status was, may or may not have been H1B. One Japanese woman at the observatory, born in the USA, might be moving to Japan depending on what our new POTUS does.