California Gov. Gavin Newsom on Sunday vetoed a landmark bill aimed at establishing first-in-the-nation safety measures for large artificial intelligence models.

The decision is a major blow to efforts attempting to rein in the homegrown industry that is rapidly evolving with little oversight. The bill would have established some of the first regulations on large-scale AI models in the nation and paved the way for AI safety regulations across the country, supporters said.

Earlier this month, the Democratic governor told an audience at Dreamforce, an annual conference hosted by software giant Salesforce, that California must lead in regulating AI in the face of federal inaction but that the proposal “can have a chilling effect on the industry.”

The proposal, which drew fierce opposition from startups, tech giants and several Democratic House members, could have hurt the homegrown industry by establishing rigid requirements, Newsom said.

“While well-intentioned, SB 1047 does not take into account whether an AI system is deployed in high-risk environments, involves critical decision-making or the use of sensitive data,” Newsom said in a statement. “Instead, the bill applies stringent standards to even the most basic functions — so long as a large system deploys it. I do not believe this is the best approach to protecting the public from real threats posed by the technology.”

Newsom on Sunday instead announced that the state will partner with several industry experts, including AI pioneer Fei-Fei Li, to develop guardrails around powerful AI models. Li opposed the AI safety proposal.

The measure, aimed at reducing potential risks created by AI, would have required companies to test their models and publicly disclose their safety protocols to prevent the models from being manipulated to, for example, wipe out the state’s electric grid or help build chemical weapons. Experts say those scenarios could be possible in the future as the industry continues to rapidly advance. It also would have provided whistleblower protections to workers.

The legislation is among a host of bills passed by the Legislature this year to regulate AI, fight deepfakes and protect workers. State lawmakers said California must take actions this year, citing hard lessons they learned from failing to rein in social media companies when they might have had a chance.

Proponents of the measure, including Elon Musk and Anthropic, said the proposal could have injected some levels of transparency and accountability around large-scale AI models, as developers and experts say they still don’t have a full understanding of how AI models behave and why.

The bill targeted systems that require more than $100 million to build. No current AI models have hit that threshold, but some experts said that could change within the next year.

“This is because of the massive investment scale-up within the industry,” said Daniel Kokotajlo, a former OpenAI researcher who resigned in April over what he saw as the company’s disregard for AI risks. “This is a crazy amount of power to have any private company control unaccountably, and it’s also incredibly risky.”

The United States is already behind Europe in regulating AI to limit risks. The California proposal wasn’t as comprehensive as regulations in Europe, but it would have been a good first step to set guardrails around the rapidly growing technology that is raising concerns about job loss, misinformation, invasions of privacy and automation bias, supporters said.

A number of leading AI companies last year voluntarily agreed to follow safeguards set by the White House, such as testing and sharing information about their models. The California bill would have mandated AI developers to follow requirements similar to those commitments, said the measure’s supporters.

But critics, including former U.S. House Speaker Nancy Pelosi, argued that the bill would “kill California tech” and stifle innovation. It would have discouraged AI developers from investing in large models or sharing open-source software, they said.

Newsom’s decision to veto the bill marks another win in California for big tech companies and AI developers, many of whom spent the past year lobbying alongside the California Chamber of Commerce to sway the governor and lawmakers from advancing AI regulations.

Two other sweeping AI proposals, which also faced mounting opposition from the tech industry and others, died ahead of a legislative deadline last month. The bills would have required AI developers to label AI-generated content and ban discrimination from AI tools used to make employment decisions.

Washington — Sen. JD Vance and Minnesota Gov. Tim Walz will face off on Tuesday in the first and only vice presidential debate of the cycle, as the two candidates look to prop up the Republican and Democratic tickets with fewer than 40 days until Election Day.

The debate, hosted by CBS News at the CBS Broadcast Center in New York City, will be moderated by “CBS Evening News” anchor and managing editor Norah O’Donnell and “Face the Nation” moderator and CBS News chief foreign affairs correspondent Margaret Brennan.

Here’s what to know about how the candidates are preparing for the debate:

How JD Vance is preparing for the VP debate

The Ohio Republican has been preparing for the debate for more than a month, a source directly involved told CBS News, including with “murder board” sessions with a small team that includes Vance’s wife and his advisers, along with senior Trump adviser Jason Miller.

Among Vance’s main focuses during the preparation has been studying Walz’ debate style and policy record, the source said, noting that Vance will attempt to highlight what he sees as the Minnesota governor’s left-wing views during the debate.

Vance told reporters last week that his plan is to break down what the Trump-Vance administration would do to make “life better” and connect that to policy.

“So, we’re studying up as much as we can on the issues that matter to the American people, and I’m looking forward to it,” Vance said.

House Majority Whip Tom Emmer, a Minnesota Republican, is standing in for Walz during Vance’s debate prep, four sources familiar with the preparations told CBS News. Emmer and Walz have deep roots in Minnesota and are close in age. 

Emmer told ABC’s “This Week” on Sunday that he’s known Walz for decades and has spent the last month working to “get his phrases down, his mannerisms.”

“My job was to be able to play Tim Walz so JD Vance knows what he’s going to see,” Emmer said.

How Tim Walz is preparing for the VP debate

Walz has been preparing for the debate with a close team of advisers, a source familiar with the preparations told CBS News. Some of the people involved also helped Vice President Kamala Harris take on former President Donald Trump, among others, like a long-time aid to Walz who worked with him during his bids for governor. 

For Walz, whose name recognition was until recently limited outside of Minnesota, the focus is on continuing to introduce himself to the American people, according to the source. He’ll also work to highlight Harris’ vision for the nation’s path forward. 

“You’ll hear me talk like I have about things that impact Americans, making sure they have the opportunity to thrive, making sure that we’re being factual in how we talk about that,” Walz told MSNBC’s Rachel Maddow of the debate earlier this month. “And so I’m looking forward to it. I’ll work hard, that’s what I do.” 

During debate prep, Transportation Secretary Pete Buttigieg is standing in for Vance, a campaign official familiar with the preparation told CBS News. The former mayor of South Bend, Indiana, also assisted Harris during her debate prep in 2020, and is close in age to Vance. 

When and how to watch the presidential debate 

Debate coverage on CBS News 24/7 begins at 4 p.m. ET, with the debate getting underway at 9 p.m. ET on Oct. 1.

The 90-minute debate will be streamed on CBS News 24/7 and Paramount+ across all available platforms and CBSNews.com. The debate will also be simulcast across other broadcast and cable networks.

contributed to this report.