A federal judge ruled Tuesday that Mahmoud Khalil, a former green card holder who led pro-Palestinian protests at Columbia University where pamphlets written by Hamas state media were distributed, could challenge the Trump administration’s right to detain him for deportation.

A Louisiana immigration judge has ruled that the U.S. can deport Mahmoud Khalil based on the federal government’s argument that he poses a national security risk. His lawyers are expected to appeal, and a federal judge in New Jersey has temporarily barred Khalil’s removal from the country.