Some of my favorite people to meet in college were foreign students. You get to meet diverse people and learn about the world. It's only a win if college is 20% cheaper this year. It's not.
Foreign money coming in will have to be made up elsewhere. It will be made up by raising tuition on remaining students. Schools that have a small enough applicant pool will price out their applicants and close. Likely they will be replaced by for-profit grifts that are much more affordable but don't actually do anything for the students except bilk them. The largest most international most diverse most administratively bloated schools will be fine. It's the small mostly-white rural colleges that will suffer the most.
Student enrollment in the US is declining and the big problem for colleges the past few years has been a worry about not having enough students. So it's not clear why US students were struggling to get a college spot.
And if you mean them getting spots in the more prestigious institutions, well, it's not clear whether that will even happen (the few thousand international students admitted to the top universities are not the ones that are likely to decline their acceptance letters), but even if it did, well, those universities are simply not as prestigious anymore.
Attracting the best talent from anywhere in the world is a huge part of what created their prestige, and that's even before we get to how they're losing funding, and professors and researchers to other countries.
Zero sum ass mentality. Top performing international students are likely to start companies and create jobs which is great for US high school and college students.
What about them? Competent domestic students are not being crowded out by international students. Competent domestic workers are not being crowded out by immigrants. The opposite is happening, immigrants create new opportunities for natives out of thin air. That doesnt mean that natives dont, they both do.
Immigrants make up 14% of the population but start more than 20% of businesses.
44% of fortune 500 companies are founded by immigrants or their children. Steve Jobs' dad was a Syrian immigrant student. Elon Musk was on F1, J1, and H1B visa.