The Trump administration is seeking to deport a Columbia student because his activities could “potentially undermine” the Middle East peace process, according to a memo from Secretary of State Marco Rubio that was reviewed by The New York Times.

The student, Mohsen Mahdawi, 34, is a legal permanent resident who has spent a decade in the United States. Until this week, he had been in hiding, for fear that the administration would seek to deport him after he led pro-Palestinian demonstrations at the school. But on Monday he showed up at an immigration services center in Vermont, expecting to take the test that would allow him to become a naturalized citizen.

Instead, he was detained by Department of Homeland Security agents, who relied on Mr. Rubio’s memo as the justification for the arrest. Mr. Rubio cited the same law that has been used to justify the detention of Mr. Mahdawi’s fellow Columbia protester, Mahmoud Khalil.

The law, which Mr. Khalil’s lawyers have challenged in federal court, allows Mr. Rubio to initiate deportation proceedings against anyone whose presence in the United States can reasonably be considered to hurt American foreign policy goals.

Last week, an immigration judge found that Mr. Rubio’s memo alone allowed the Trump administration to meet the burden of proof necessary for deporting Mr. Khalil, whom the secretary accused of undermining the fight against antisemitism. The judge’s decision affirmed, for the time being, Mr. Rubio’s power to pick and choose which noncitizens — even those with legal residency — can be deported.

Evidence submitted by the Department of Homeland Security and reviewed by The Times did not include any allegations of antisemitism against Mr. Khalil himself, apart from the flat declaration in Mr. Rubio’s memo.