In a dramatic escalation of immigration enforcement, U.S. authorities on Monday arrested Mohsen Mahdawi, a Palestinian student at Columbia University, during what was supposed to be his final step in becoming a U.S. citizen. The arrest occurred while Mahdawi was attending a scheduled interview with immigration officials.

Mahdawi, a legal permanent resident since 2015, co-founded a pro-Palestinian student group at Columbia and was set to graduate next month. He had already secured admission to a master’s program at the university for the fall. His lawyers, now seeking emergency relief from a federal judge, argue that the Trump administration’s actions violate constitutional protections, especially regarding free speech and political expression.

Mahdawi’s arrest follows the earlier detention of his co-organizer Mahmoud Khalil, and mirrors similar cases involving student activists like Rumeysa Ozturk of Tufts University and Yunseo Chung of Columbia, both of whom are also facing deportation attempts—currently halted by court orders.

A video shared online by friends showed masked agents escorting Mahdawi into a black SUV. Vermont Senator Bernie Sanders, along with other lawmakers, condemned the arrest, calling it a dangerous precedent. District Judge William Sessions has issued a temporary restraining order to prevent Mahdawi’s removal from Vermont pending further legal proceedings.

Free speech advocates and critics across the political spectrum have voiced concern that such arrests could chill political expression and disproportionately target noncitizens involved in peaceful protest.