Secretary of State Marco Rubio said Wednesday the effort to deport Mahmoud Khalil, a Columbia University grad student and prominent leader of pro-Palestinian protests on campus, was about conduct, not speech.

“These lunatics are running around with covers on their face, screaming terrifying things,” Rubio said while in Ireland Wednesday. “If you told us that’s what you intended to do when you came to America, we would have never let you in. If you do it once you get in, we’re going to revoke it and kick you out.”

As secretary of state, Rubio has sweeping powers under the law.

“Which actually allows the secretary of state to make a determination that somebody’s presence in the United States is contrary to foreign policy goals and that therefore that person should be removed,” Camille Mackler, an immigration attorney, said.

It’s as sweeping as it is obscure, said Mackler, who founded the group, Immigrant ARC.

“Because it is so obscure and rarely used, we’re all sort of trying to figure out what the parameters of it are,” she said.

Khalil, a 30-year-old green card holder, is originally from Syria. He is now being detained in Louisiana. He is not facing any criminal charges.

Rubio accused Khalil of supporting Hamas and organizing anti-Jewish and antisemitic activities that shut down the campus.

“This is not about free speech,” he said. “This is about people that don’t have a right to be in the United States to begin with. No one has a right to a student visa. No one has a right to a green card, by the way.”

Immigration attorney Joseph Rose said the federal government appears to be arguing that the actions are more than just speech.

“They believe it’s this type of rabble rousing in connection with crimes that have been committed, and it’s not just an issue of pure speech,” Rose said. “When you get into the realm of national security, yes, it’s a rarely used ground for removal, but obviously they’re going to have to show the goods.”

Khalil acted as a spokesman and negotiator for a protest group, Columbia University Apartheid Divest. Protesters at Columbia last year set up tents on the South Lawn and occupied Hamilton Hall.

Khalil’s petition to fight deportation describes his arrest by immigration authorities “as retaliation against his protected speech.”

“There can be arguments made that the conclusions of the government are not founded, in other words, that they’re arbitrary, that they’re being motivated for other reasons,” Mackler said.