A federal judge ruled Wednesday that Mahmoud Khalil, a student activist whom the government is seeking to deport, was likely to prevail in his argument that his detention was unconstitutional. But he declined to issue a preliminary injunction in the case,

U.S. District Judge Michael Farbiarz said Khalil was expected to succeed in a claim that an obscure provision of immigration law was so vague as to be illegal.

But in a mixed ruling, Federal Judge Michael Farbiarz declined, for now, to order Khalil released from immigration detention.