Dozens of Liberty University alumni plan to return their diplomas in protest after the university’s leader, Jerry Falwell Jr., defended President Trump’s response to the white supremacist rally and deadly car attack in Charlottesville, Va.

When Mr. Trump declared last Tuesday that there had been “very fine people” among the white nationalists and neo-Nazis who gathered in Charlottesville, and suggested a moral equivalency between those groups and what he called the alt-left, he found few prominent allies even among Republicans.

But Mr. Falwell — the conservative evangelical leader who became Liberty’s president after his father, Jerry Falwell Sr., died in 2007 — responded glowingly, tweeting the next morning: “Finally a leader in WH. Jobs returning, N Korea backing down, bold truthful stmt about #charlottesville tragedy. So proud of @realdonaldtrump.”

To many alumni, already uneasy because of Mr. Falwell’s public statements and their reflection on the university, this was the last straw.