Claire Shipman is only days into her job as acting president of Columbia University but is already being targeted by a prominent House Republican who questions her commitment to fighting antisemitism on campus.

Ms. Shipman, in a private text message in December 2023 to Nemat Shafik, who was then Columbia’s president, referred to congressional hearings into campus antisemitism as “capital hill nonsense,” according to a transcript of the exchange released by the House Committee on Education and the Workforce as part of an investigative report last year.

The comment is coming back to haunt Ms. Shipman. Representative Elise Stefanik, who is remaining in the House after President Trump withdrew her nomination to be U.S. ambassador to the United Nations, seized on the remark during a television interview Sunday, predicting that Ms. Shipman will not last long in her new position.

“It’s already come out that she has criticized and belittled the House investigation and the accountability measures and has failed to protect Jewish students,” Ms. Stefanik said on Fox News’s “Sunday Morning Futures.”

“It’s untenable for her to be in this position, and I think it is only going to be a matter of weeks before she’s forced to step down as well,” she added.

On X, Ms. Stefanik, whose pointed questioning of Ivy League presidents about antisemitism during the committee hearings sparked the departures of the presidents of Harvard and the University of Pennsylvania, gave other details.

She wrote that last April, when Ms. Shipman testified alongside Dr. Shafik at the committee hearings into antisemitism, Ms. Shipman had “cheered in the back anteroom about how it was going so well for them,” even as a pro-Palestinian encampment on Columbia’s lawns was forming that same day.

In the related fallout, Dr. Shafik resigned in August, and Dr. Katrina Armstrong, her interim replacement, left her post on Friday.

“Two Presidents later, here we are,” Ms. Stefanik posted on Saturday. “They will be onto yet another Columbia President very, very soon after this one. They still don’t get it.”

The federal government’s Task Force to Combat Antisemitism pulled about $400 million in federal research grants from Columbia on March 7. A week later, it issued a letter outlining nine steps it wanted Columbia administrators to take as a precondition to start negotiations about returning the money.

Dr. Armstrong pledged to comply with the conditions in a letter sent to the federal government on March 21. But a week later, after media reports that she had played down the extent of the changes at a private faculty meeting, Columbia announced that she was stepping down. The board of trustees selected Ms. Shipman as her acting replacement until a permanent president could be hired.

In her private text to Dr. Shafik in December 2023, Ms. Shipman showed an interest in engaging the pro-Palestinian movement rather than disciplining it. She suggested that Columbia “think about how to unsuspend the groups” — a reference, the report said, to Students for Justice in Palestine and Jewish Voice for Peace, two student groups that had been suspended for repeatedly violating university rules.

She also suggested working with Rashid Khalidi, a Palestinian historian, now retired, who was affiliated with Columbia’s Center for Palestine Studies. In the House committee’s description, this amounted to “working behind the scenes to appease the University’s antisemitic actors.”

“FINDING: COLUMBIA’S LEADERS EXPRESSED CONTEMPT FOR CONGRESSIONAL OVERSIGHT OF CAMPUS ANTISEMITISM,” the report trumpeted over its description of Ms. Shipman’s text message.

A Columbia spokeswoman, Samantha Slater, said on Monday that the university was proceeding with the changes it had promised, which include empowering a unit of campus police with arrest powers and increasing oversight of a Middle East studies department.

“We are focused on doing what is right and honoring our commitments to create a Columbia community where students are safe and able to flourish,” she said in a statement. “This will secure Columbia’s future.”

Ms. Shipman, who has been on the Columbia board since 2013 and became co-chair in 2023, did not address the controversy Monday in her first formal letter introducing herself to the campus in her new role. But she said she would follow through on Columbia’s pledge to address the Trump administration’s concerns.

“We will continue to build on the significant progress we’ve made, and the plan outlined to move our community forward,” she wrote.

“My request, right now, is that we all — students, faculty, staff, and everyone in this remarkable place — come together and work to protect and support this invaluable repository of knowledge, this home to the next generation of intellectual explorers, and this place of great and continuing promise,” Ms. Shipman wrote.