Harvard, M.I.T. and the University of Pennsylvania on Thursday faced threats from donors, demands that their presidents resign and a congressional investigation as repercussions mounted over the universities’ responses to antisemitism on campus.

At Penn, university trustees discussed the future of Elizabeth Magill, its president, whose congressional testimony on Tuesday set off a furor when she dodged the question of whether she would discipline students for calling for the genocide of Jews.

Her answers and similar comments by Claudine Gay of Harvard and Sally Kornbluth of M.I.T. at a House committee meeting set off accusations that they were doing little to protect their own students. All three said they had taken action against antisemitism, but critics argued they had not done enough or were even fostering antisemitism on their campuses.

In response, a House committee opened an investigation into the three institutions as its chairwoman criticized the schools for failing to tackle the “rampant antisemitism” on their campuses after the Hamas attack on Israel on Oct. 7 and the subsequent Israeli invasion of Gaza.