The U.S. Senate debate in the nation’s largest state wasn't broadcast on statewide TV but it was livestreamed. San Francisco Chronicle Senior Political Writer Joe Garofoli and Editorial Page Editor John Diaz break down the first - and likely only - showdown between the two candidates.

The event, billed as a “conversation” at the Public Policy Institute of California in San Francisco, with the nonprofit’s president doling out questions, was a historic occasion: Not since 2000 had Feinstein engaged an election challenger one-on-one. She’s had no pressure to do so until now, having faced only nominal opposition.

De León, however, is a different brand of challenger, even though he trails in the polls. He’s the author of California’s main sanctuary legislation, giving him credibility with the Democratic “resistance” to President Trump. It helped win him the endorsement of the state Democratic Party over Feinstein, a stunning rebuke to a senator seeking her fifth full term.

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