Inside Trump’s Crackdown on Dissent: Obscure Laws, ICE Agents and Fear

For months now, President Trump has been threatening to deport foreign students who took part in last year’s campus protests over the Israel-Hamas war.

Behind the scenes, his administration got to work.

Investigators from a branch of Immigration and Customs Enforcement that typically focuses on human traffickers and drug smugglers scoured the internet for social media posts and videos that the administration could argue showed sympathy toward Hamas, administration officials said. The investigators handed over reports on multiple protesters to the State Department, which used an obscure legal statute to authorize the arrest over the weekend of a 30-year-old lawful permanent resident: Mahmoud Khalil.

Mr. Trump said this week that Mr. Khalil’s case was the first of “many to come.”

Civil rights groups say the arrest of Mr. Khalil, who is a legal permanent resident and is married to an American citizen, is a clear violation of the First Amendment. But it also illustrates how Mr. Trump is using the tools of the federal government to launch a crackdown not only on those who break the law — but also on dissent more broadly.

“Freedom of speech has limitations,” Thomas D. Homan, who is overseeing Mr. Trump’s deportation operation, said on Wednesday during a meeting of New York lawmakers in Albany. “We consider him a national security threat.”

Mr. Khalil has not been charged with any crime. Instead, the government is using a provision in the Immigration and Nationality Act to argue that his actions during protests at Columbia University harmed U.S. foreign policy interests by fomenting antisemitism.