I agree with you 100%, but people who complain about immigration would argue that they're taking away the opportunities for Americans for the same education / positions.
Heck, that's what they say about undocumented migrant workers in agriculture. But seeing them in positions in the "intellectual elite" is even more threatening to them because such positions are seen as a position of power.
I can confirm based on my Texan friend who voted for Trump that when he sees so many foreign students, he thinks of the potential American students that were "displaced" by them. I put displaced in quotes because it's not true that they could all be backfilled by americans (there are only so many people who graduate with an undergrad degree in EE or Physics each year).
The schools aren't the problem? How do you think the parents got into a position where they don't push their kids to succeed? Have you been to an inner-city school? How about a school in Mississippi or South Carolina?
The government defunded the schools and created a culture of anti-intellectualism. Fixing education is just about as perfect a solution you can get to the myriad of problems this country faces.
Heck, that's what they say about undocumented migrant workers in agriculture. But seeing them in positions in the "intellectual elite" is even more threatening to them because such positions are seen as a position of power.