The Trump administration has vowed to continue an immigration crackdown against campus activists who it deems are antisemitic, following the controversial arrest of Columbia University protest leader Mahmoud Khalil on Sunday. “This is the first arrest of many to come,” President Donald Trump warned in a post on Truth Social, accusing Khalil of being a “Radical Foreign Pro-Hamas Student.” “We know there are more students at Columbia and other Universities across the Country who have engaged in pro-terrorist, anti-Semitic, anti-American activity, and the Trump Administration will not tolerate it,” Trump added. Secretary of State Marco Rubio had a similar message Sunday. “We will be revoking the visas and/or green cards of Hamas supporters in America so they can be deported,” he wrote in a statement. The White House also posted about the arrest, telling Khalil, “Shalom, Mahmoud,” using the Hebrew word for goodbye. Khalil, a legal permanent U.S. resident who was born in Palestine, graduated from Columbia in late 2024. He was arrested Sunday inside the university-owned apartment where he lives with his wife, a U.S. citizen. A group of plainclothes Immigration and Customs Agents agents followed the couple into the building and said Khalil was under arrest because his student visa had been revoked by the State Department, his attorney said. Columbia has a general policy of requiring immigration agents to present a warrant before entering campus buildings unless in exigent circumstances. The university declined to answer The Independent when asked about whether the agents shared their warrant before the arrest. Khalil’s wife, and later his attorney, told the agents he had a green card, prompting the agents to say that had been revoked, too. Only an immigration judge can revoke a green card, according to experts. A spokesperson for the Department of Homeland Security, which oversees ICE, told The Independent on Sunday that Khalil was arrested “in support of President Trump’s executive orders prohibiting anti-Semitism.” Khalil “led activities aligned to Hamas, a designated terrorist organization,” they added. In January, a Trump executive order vowed to deport immigrant students who broke U.S. laws during the wave of campus protests across the U.S. last year amid the Israel-Hamas war. A White House fact sheet at the time suggested the administration would attempt to deport such immigrants on even broader, viewpoint-based grounds, going after all those who joined the protests or were “Hamas sympathizers,” provisions likely to face legal challenges on constitutional free speech grounds. Following his arrest, Khalil, who served as a negotiator between students and administrators during tense encampment and building occupation protests on campus, immediately sought a habeas corpus petition challenging the legality of his detention on First Amendment and due process grounds. Nonetheless, ICE moved the leader to a detention facility in Louisiana, hundreds of miles from his attorney and family. A federal judge on Monday paused any removal proceedings against Khalil until at least after a hearing in New York on Wednesday. In a court petition obtained by Courthouse News, Khalil accused the government of “open repression of student activism and political speech, specifically targeting students at Columbia University for criticism of Israel’s assault on Gaza.” The “U.S. government has made clear that they will use immigration enforcement as a tool to suppress that speech.” he added. The Center for Constitutional Rights has joined in the effort to challenge Khalil’s detention in Louisiana, according to court documents. Civil liberties advocates expressed alarm over the arrest, arguing it was a sign of authoritarianism. “Arresting and threatening to deport students because of their participation in political protest is the kind of action one ordinarily associates with the world’s most repressive regimes. It’s genuinely shocking that this appears to be what’s going on right here,” Jameel Jaffer, executive director of the Knight First Amendment Center at Columbia, wrote in a statement in Forever Wars. “Universities must recognize that these actions pose an existential threat to academic life itself. They must make clear, through action, that they will not sit on the sidelines as the Trump administration terrorizes students and faculty alike and runs roughshod over individual rights and the rule of law." By Monday afternoon, a growing coalition including the First Amendment watchdog FIRE and a number of congressional Democrats were calling for the expulsion effort to be immediately dropped and accused the Trump administration of attempting to criminalize speech the White House disagreed with. “[T]he government has not made clear the factual or legal basis for Mr. Khalil’s arrest. The statements the government has released suggest its decision may be based on his constitutionally protected speech,” wrote FIRE in a letter to DHS Secretary Kristi Noem and other Trump administration officials on Monday. Donna Lieberman, CEO of the New York Civil Liberties Union (NYCLU), said on Monday that Khalil’s arrest “reeks of McCarthyism”. She added that the federal government had “no authority” to strip his permanent residence status over political speech. At a press conference, faculty at Columbia also called for Khalil’s release and attacked his detention as unlawful. “Universities cannot exist when students are persecuted, arrested and disappeared for their political beliefs,” said Nara Milanich, a professor at Columbia’s Barnard College. Students told The Independent the arrest was creating a climate of fear of further ICE operations on campus. “Given the magnitude of statements made by the president and his administration, I feel I am not safe knowing they’re around campus,” one international student told The Independent. Protests in support of Khalil are expected in New York on Monday afternoon. Over 1.5 million people sent letters in support of the protest leader after the arrest. Prior to his detention, Khalil sent multiple messages to senior campus officials, asking for protection given the “vicious, coordinated, and dehumanizing doxxing campaign” he faced from individuals calling for his arrest, including Columbia faculty, Zeteo reports. After the arrest, the Zionist organization Betar, among those Khalil mentioned in his messages to staff, appeared to take credit for the detention. “Shalom Mahmoud will be said many, many more times,” the group wrote on X. “He complained to Columbia about Betar. We confirm we have provided thousands of names to the ⁦@realDonaldTrump⁩ administration. Many more will go!” The group has previously used aggressive tactics, including offering rewards to give pro-Palestinian activists “beepers,” a seeming reference to Israel’s recent pager-based explosive attack on Hezbollah that killed numerous civilians alongside militants. The Trump administration has made tackling what it deems to be antisemitism on campus a major policy priority, launching investigations of major Ivy League schools and pulling $400 million in federal funding from Columbia. The effort to deport Khalil comes after a year of tense confrontations and debates between school administrators and student activist leaders around the country. At many colleges and universities, including Columbia, protesters were accused of making Jewish students feel unsafe — both due to the efforts of conservatives to tar all criticism of Israel as antisemitic, as well as real instances of anti-Jewish hate that surged in frequency alongside Islamophobic hate on some campuses. Among Democrats, the issue is another place where the party is divided. Many Democrats spent much of 2024 condemning the protests as broadly antisemitic in nature, though progressives including Palestinian-American Rep Rashida Tlaib have argued against those characterizations of the protests without endorsing them explicitly. “Free Mahmoud Khalil. This is straight out of the fascist playbook,” Tlaib wrote on X on Monday. “Criminalizing dissent is an assault on our First Amendment and freedom of speech. Revoking someone’s green card for expressing their political opinion is illegal. Protesting genocide is not a crime.”