You can buy entry to the US, and Khan sells it.
EB-5 Program. Under this program, entrepreneurs (and their spouses and unmarried children under 21) are eligible to apply for a green card (permanent residence)
The EB5 Investor visa program is one of the fastest growing ways to gain permanent US residency. By following the requirements and meeting qualifications, the EB5 visa provides a method for foreign nationals who invest money in the U.S. to obtain a green card for themselves, their spouse and all children under the age of 21.
http://www.centralfloridaeb5regionalcenter.com/
The E-2 nonimmigrant classification allows a national of a treaty country (a country with which the United States maintains a treaty of commerce and navigation) to be admitted to the United States when investing a substantial amount of capital in a U.S. business.
Treaty investors and employees may be accompanied or followed by spouses and unmarried children who are under 21 years of age.
https://www.uscis.gov/working-united-states/temporary-workers/e-2-treaty-investors
Does the definition of investment include making sizable political campaign contributions?