Depends on the field. Students from developing countries are usually not lower class, but, compared to Americans, have much lower income. In many fields, especially STEM ones that actually provide tutition waivers, these students make up significant chunk of the students. There is liberal arts, but tuition waivers are much more rare there.

I’m sure this is what the Trumpists were really after. He is not very friendly to immigrants, after all. And STEM doesn’t really mesh with make America great again mantra of bringing back low skilled manufacturing jobs.