The deportation proceedings against Mahmoud Khalil, a Syrian-born Palestinian who played a major role in the anti-Israel protests and encampments at Columbia University last year, illustrate how some foreign nationals granted residency in the United States betray that privilege and exploit the country’s benefits and privileges in order to sow disruption and promote hateful movements.

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.

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.