Former Harvard President Larry Summers stepped up his criticism of the Ivy League university’s leadership in a series of tweets on Tuesday expressing concern for how the school is addressing antisemitism, which has dramatically increased on campus since the Oct. 7 Hamas terror attacks in Israel.

“My confidence in Harvard leadership’s ability and will to confront anti-semitism and the demonization of Israel continues to decline,” Summers, a former U.S. Treasury secretary, wrote on X Tuesday morning. “Unfortunately, it is becoming ever clearer why Harvard ranks first on anti- semitism, even as it ranks last on upholding free speech.” 

Summers, a board member of the newly founded University of Austin, continued, “The executive board of Harvard’s Center for Middle East Studies, acting for the Center, not in their individual capacities, has endorsed a statement demonizing Israel.” 

“I cannot think of a worse stretch in Harvard history than the last few months. I have no doubt that all members of the Corporation are deeply devoted to Harvard,” the president emeritus wrote, referring to the Harvard Corporation, the university’s main governing body. “As the institution’s ultimate fiduciaries, I hope they will take appropriate accountability and enable a restoration of confidence.” 

Summers’ post on Tuesday followed his tweet on Jan. 21, in which he slammed the selection of Harvard professor Derek Penslar as the co-chair of a newly formed university task force on antisemitism. Alan Garber, Harvard’s interim president, unveiled a pair of task forces last week aimed to fight both antisemitism and Islamophobia.

The appointment of Penslar, a historian and the director of Harvard’s Center for Jewish Studies,  drew the ire of Jewish communal leaders and prominent figures at Harvard over comments he made in recent weeks minimizing concerns over antisemitism at the university, and for past statements he has made about Israel. “Outsiders took a very real problem and proceeded to exaggerate its scope,” Penslar told JTA earlier this month. 

Summers’ criticism of Harvard stands in contrast from his previous praise of how the school’s leadership was dealing with antisemitism. Earlier this month, he applauded President Claudine Gay for her decision to step down due to allegations of plagiarism, coupled with her handling of the antisemitism controversy. 

“I admire Claudine Gay for putting Harvard’s interests first at what I know must be an agonizingly difficult moment,” Summers said in a statement on Jan 2.  

Harvard did not respond to the Oct. 7 Hamas attacks for two days. By then, a letter signed by more than three dozen student groups holding Israel alone responsible for the massacre had gone viral. In the last several months, antisemitic incidents at the Cambridge campus have skyrocketed. Six Jewish students filed a federal lawsuit against the school this month, calling it a “bastion of rampant anti-Jewish hatred and harassment.”

Jewish Insider’s senior national correspondent Gabby Deutch contributed reporting.