You need to start with the universities that import foreigners into graduate schools to displae natural-born citizens. They do the basic research work very, very cheaply so their tenured professors can bank more of the grant money that would otherwise need to go to support U. S.=born native scholars/ Then these foreign-born graduates get the corporate laboratory jobs and professorships, cheapening them also. Then they start bringing in their relatives.
Having a grad student (foreign or domestic) is not cheap. Professors need to pay tuition, research assistantship plus overhead, that could amount to upwards of 50-60 k per year depending on the school and discipline. Most domestic students do not go into grad school because there are no faculty positions. The only reason you want to do a PhD is to become a professor.
But the CCP's elite is willing and able to pay any price.