A federal judge ruled Wednesday that the Trump administration's efforts to deport Columbia University pro-Palestinian activist Mahmoud Khalil, in part to protect U.S. foreign policy, is likely unconstitutional.

Khalil, a legal U.S. resident, was detained by federal immigration agents on March 8 in the lobby of his university-owned apartment, the first arrest under President Donald Trump’s widening crackdown on students who joined campus protests against Israel’s war in Gaza.

A federal judge ruled Wednesday that the Trump administration’s effort to deport pro-Palestinian activist Mahmoud Khalil is likely unconstitutional, but the judge stopped short of freeing him from jail.