If the Trump Administration comes out on the wrong side of this fight, it will be because defending free speech remains a politically lucid and powerful principle.

The Trump administration’s detention of a green-card holder who was a leader in the Columbia University protests against Israel has put a face on the debate over immigration and the limits of free speech, with a sympathetic twist: The man, Mahmoud Khalil, is married to an American, and they are expecting their first child next month.

A DHS official defended Khalil’s detention in an interview on Thursday but did not provide additional details for his arrest.