A legal battle over an arrested Palestinian activist and Columbia University student that has become a flashpoint of the Trump administration’s immigration policy will play out in federal court, with the U.

President Donald Trump is warning that the arrest and possible deportation of a Palestinian activist who helped lead protests at Columbia University will be the first “of many to come” as his administration cracks down on protests against the war in Gaza.

Mahmoud Khalil, a 29-year-old legal resident of the United States, was arrested and detained by federal agents Sunday, after his green card was revoked by the Trump administration.