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.

The Trump administration has not been subtle about its intentions. A White House official, speaking anonymously to the Free Press, told the right-leaning media organization that Khalil’s arrest would be a “blueprint” for other actions.