California Governor Gavin Newsom vetoed Senate Bill (SB) 1047 on Sunday, concluding the bill was insufficiently broad in its regulation of large-scale artificial intelligence (AI) models, and lacked empirical support.

Newsom viewed SB 1047 as premature and overly sweeping, noting that it “applies stringent standards to even the most basic functions” of AI, so long as the system deploying it is large. Newsom further explained:

By focusing only on the most expensive and large-scale models, SB 1047 establishes a regulatory framework that could give the public a false sense of security about controlling this fast-moving technology. Smaller, specialized models may emerge as equally or even more dangerous than the models targeted by SB 1047.

SB 1047 passed the California State Assembly in late August with a 49-15 vote. It had received support from Tesla CEO Elon Musk on X (formerly Twitter) but was criticized by California Congresswoman Nancy Pelosi for its potential detriments to innovation and the US AI ecosystem.

Although SB 1047 was vetoed, Newsom recently signed three other landmark AI bills into law in mid-September. Each law serves to mitigate election-related content created by AI, particularly “deepfakes.” California remains a pioneer in AI legislation for the United States, recognizing its responsibility as “home to 32 of the world’s 50 leading AI companies.”

SB 1047, first introduced by Senator Scott Wiener, emerged amidst a global discussion about what the thresholds should be for AI regulation. One school of thought supports regulating AI based on “the cost and number of computations needed to develop an AI model.” SB 1047 fell in this category as it targeted large-scale models. The opposing view believes that regulations should focus on actual risks posed by AI systems, regardless of their size and computational cost.

Newsom has announced more initiatives to come to protect Californians against AI misuse, including collaborating with the “godmother of AI,” Dr. Fei-Fei Li.