On Monday, Anthropic announced an official endorsement of SB 53, a California bill from state senator Scott Wiener that would impose first-in-the-nation transparency requirements on the world’s largest AI model developers. Anthropic’s endorsement marks a rare and major win for SB 53, at a time when major tech groups like the Consumer Technology Association (CTA) and Chamber for Progress are lobbying against the bill. “While we believe that frontier AI safety is best addressed at the federal leve...