The University of Southern California abruptly canceled a high-profile California gubernatorial primary debate scheduled for Tuesday, following criticism that the invited candidate lineup lacked racial diversity. The debate, organized by USC’s Dornsife Center for the Political Future, had initially included six candidates: Republicans Steve Hilton and Chad Bianco, and Democrats Tom Steyer, Katie Porter, Eric Swalwell, and Matt Mahan.

Absent from the lineup were established Democratic candidates of color, including former Los Angeles Mayor Antonio Villaraigosa, former Health and Human Services Secretary Xavier Becerra, former State Controller Betty Yee, and State Superintendent Tony Thurmond.

USC had defended its selection process, citing a “data-driven” formula developed by a university professor that weighed polling and fundraising. Critics, however, argued the methodology produced a skewed outcome in a crowded race with no clear frontrunner.

The controversy intensified after California legislative leaders demanded that the university expand the debate field. In a letter to USC President Beong-Soo Kim, lawmakers wrote that every excluded leading candidate was a person of color and urged voters to boycott the event if the university did not revise its criteria.

Despite standing by its formula, USC ultimately reversed course late Monday, announcing the debate’s cancellation after organizers failed to reach an agreement on expanding the stage. The university said the selection concerns had “created a significant distraction from the issues that matter to voters.”

The decision comes in a crowded primary to replace Gov. Gavin Newsom, with no candidate polling above 20% and multiple contenders clustered within single digits. California’s top-two primary system adds further stakes, as Democrats fear vote fragmentation could allow two Republicans to advance.

San Jose Mayor Matt Mahan, whose inclusion drew scrutiny, criticized the cancellation, writing that the “answer isn’t to cancel debates, it’s to hear all voices.” Villaraigosa, one of the excluded candidates, praised the decision, calling it “the right call, even if it came late and under pressure.”

The California gubernatorial primary is set for June 2, 2026.