Many of the liberal Jewish and civil rights organizations and lawmakers who protested federal efforts to deport Columbia University anti-Israel protest leader Mohsen Mahdawi are so far silent on new revelations about Mahdawi’s lengthy history of antisemitic and pro-terrorist social media posts. 

Mahdawi, a graduate student at Columbia facing deportation for his role in campus protests, wrote posts over the span of 15 years that supported armed violence and called to “annihilate the Jews,” according to a 100-page investigation published Wednesday by journalists David Collier and Rachel Feldman — with Arabic-to-English translations confirmed by Jewish Insider. 

Mahdawi, a 35-year-old green card holder and West Bank native, pledged in a 2010 Facebook post, “soon, very soon, we will annihilate the Jews.” He also praised Hamas and honored deceased terrorists in several posts on Instagram and Facebook, declaring that Palestinians have the capacity and conviction “to kill and to wound.” 

Some of the posts were published as recently as 2024, while Mahdawi was an undergraduate student at Columbia, where he is now enrolled in the Ivy League’s School of International and Public Affairs. 

The report states that in 2015, the FBI investigated Mahdawi after a Vermont gun-store owner alleged that he had sought to purchase a sniper rifle and machine gun while claiming to have considerable firearm experience, and allegedly said he had used modified submachine guns “to kill Jews while he was in Palestine.” Another man separately alleged Mahdawi told him, “I like to kill Jews.” Mahdawi denied the allegations. The investigation ended that year, and no charges were filed.

Mahdawi was arrested and detained by federal immigration officers in April 2025 while appearing at a U.S. citizenship interview in Vermont, where he resides. This summer, a federal appeals court reversed a decision that had released Mahdawi from Immigration and Customs Enforcement detention on bail last year. The ruling does not require Mahdawi to return to a detention center, but he is potentially at risk for rearrest.

Both J Street and the ACLU — two groups that have previously defended Mahdawi — did not respond to requests for comment from JI on Thursday, asking if the organizations would update their statements of support in light of the newly unveiled posts. Both groups have previously stated Mahdawi is being unfairly targeted by the Trump administration over his advocacy for Gaza and Palestinian rights.

In 2025, when Mahdawi was arrested, J Street President Jeremy Ben-Ami said the group was “outraged by the Trump Administration’s continued anti-democratic crackdown on Palestinian and pro-Palestinian students in the United States, and its cynical exploitation of genuine fears of antisemitism as its pretext for doing so.” 

The group encouraged people to sign a petition supporting him in late July.

Beth Jacob Synagogue, a non-denominational congregation in Vermont that co-sponsored a fundraiser last month for Mahdawi’s legal aid, also did not respond to a request for comment from JI on Thursday. 

Democratic members of Congress have also rallied in support of Mahdawi, particularly Rep. Becca Balint (D-VT). Balint, who is Jewish, led close to 70 House Democrats on a letter condemning Mahdawi’s arrest, calling it “dystopian” and motivated by “statements that the Trump Administration does not agree with.”

“It is Mr. Mahdawi’s right as a legal resident of the United States to argue for what he believes in,” the letter reads. “This most fundamental of American rights is crucial to the fabric of our country, and one that America was built upon. … We profoundly oppose unlawful abductions and expect a prompt response to our questions.”

Balint, Sanders and other Democrats also held a rally in April 2025 outside the State Department, defending Mahdawi and dismissing past allegations that he had told a gun shop owner that he had made comments about killing Jews and having built weapons for terrorist groups.

Balint, Sanders, Sen. Peter Welch (D-VT), who met with Mahdawi in detention, and other Democrats who have been vocally supportive of Mahdawi did not respond to requests for comment.

The Congressional Progressive Staff Association also hosted a happy hour with Mahdawi earlier this year.

“Mahdawi frequently speaks of justice. It is one of the central themes of the identity he presents to American audiences,” Collier and Feldman wrote in their report. “But justice requires something more fundamental: truth. After almost one hundred pages examining his words, his history and the stories upon which his public identity was built, that is where the problem with Mohsen Mahdawi ultimately lies.”

Although the report exposes dozens of Mahdawi’s most egregious comments, his extreme anti-Israel stance and support for terrorist groups has been public knowledge for years.

Mahdawi has been characterized by the Department of Homeland Security as a “ringleader” in anti-Israel protests at Columbia. It accused him of using “threatening rhetoric and intimidation” against Jewish students before graduating last year. He has not been charged with a crime.

In a “60 Minutes” interview in December 2023, Mahdawi said he could “empathize” with Hamas and its Oct. 7, 2023, attacks. “To empathize is to understand the root cause and to not look at any event or situation in a vacuum. This is for me that path moving forward,” he said. 

Meanwhile, Mahdawi is scheduled to speak at a Columbia symposium next week titled The Forever War and the First Amendment. The university did not respond to a request for comment from JI.