Campus protests are not usually aimed at a single person. But last week at the University of Pennsylvania, professors staged a rally targeting Marc Rowan, the New York private-equity billionaire.

A Penn alumnus and a major benefactor of the university, Mr. Rowan deployed his formidable resources in a relentless campaign against Penn’s president, M. Elizabeth Magill, leading to her resignation in December.

But it was what happened next that spurred the protest. Mr. Rowan sent a four-page email to university trustees titled “Moving Forward,” which many professors interpreted as a blueprint for a more conservative campus.

Amy C. Offner, a history professor who led the protest, called the document a proposed “hostile takeover of the core academic functions of the university.”

The protest of about 100 people was a sign that the discord on campus would probably continue despite Ms. Magill’s resignation, which many members of Penn’s community hoped would quell the outrage over testimony she gave at a congressional hearing that seemed to equivocate over whether students would be disciplined if they called for the genocide of the Jews.