In early March, Immigration and Customs Enforcement arrested Mahmoud Khalil—a Palestinian Columbia University graduate student, campus organizer, and legal permanent resident—and detained him for more than three months, as the Trump administration worked to strip him of his status and deport him. (Khalil has since graduated.) For many, Khalil’s arrest marked a terrifying inflection point . Here was a legal permanent resident thrown in detention for what Secretary of State Marco Rubio plainly