If you’d like to diagnose a particularly acute case of Main-Character Syndrome as it pertains to the latest college-campus handwringing, might I suggest Bill Ackman? The controversial 57-year-old hedge fund manager has injected himself into the outrage over a messy congressional hearing on antisemitism in universities this month, most notably by becoming the leading voice of an all-out pressure campaign to force Harvard’s president, Claudine Gay, to resign. After a clipped video of three university presidents testifying before Congress appeared to show them waffling when asked how their schools address hypothetical calls for a Jewish genocide, Ackman cheered the resignation...