What makes the Trump administration’s arrest and attempted deportation of Khalil so shocking is that he is accused of no actual crime. The permanent legal resident was targeted for his political beliefs: proudly pro-Palestinian, he was accused of allying himself with Hamas, a designated terrorist organization.

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

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.