Secretary of State Marco Rubio said last month that he's revoked at least 300 visas of students he described as "lunatics," citing pro-Palestinian support or activism, activities that are normally considered protected First Amendment rights, USA TODAY reported.

For hundreds of thousands of people every year who dream of studying or researching in the United States, a student visa is the golden ticket.

The Trump administration has revoked hundreds of student visas in nearly every corner of the country as part of a vast immigration crackdown – and few universities know why.