Gavin Newsom

Gavin Newsom is an American politician who served as mayor of San Francisco and later became the 40th Governor of California. He was born in San Francisco in 1967 ^[1].

Education and early business career

Newsom attended Redwood High School and later Santa Clara University ^[1]. After college he did not go directly into public office. He started a retail wine shop, and that business grew into the PlumpJack Group, which managed restaurants, hotels and wineries across California ^[1]. The company therefore spanned several parts of the hospitality trade — food service, lodging and wine production — rather than a single storefront.

Early political career

His first job in politics was on the San Francisco Parking and Traffic Commission, a body that deals with the everyday question of how vehicles, parking and street space are managed in a dense city ^[1]. He later served on the San Francisco Board of Supervisors, the legislative body of the city and county government ^[1]. In 2003 he became the youngest elected Mayor of San Francisco in a century ^[1].

Mayor of San Francisco

As mayor, Newsom directed the city-county clerk to issue marriage licences to same-sex couples ^[1]. The instruction went to an official whose office handles civil paperwork, which made the clerk's office the point where the policy took effect.

Governor of California

Newsom was elected as California's 40th Governor on 6 November 2018 ^[1]. The governor of the largest state by population is a position that reaches into many policy areas, and in Newsom's case the record that draws the most attention from people who follow technology policy concerns artificial intelligence.

Artificial intelligence legislation

On 29 September 2024 Newsom returned Senate Bill 1047 without his signature ^[2]. In California, when the legislature passes a bill it goes to the governor, who can sign it, veto it, or return it without a signature; returning a bill without signing is the formal way a governor declines to put a bill into effect.

The following year, on 29 September 2025, he signed Senate Bill 53, the Transparency in Frontier Artificial Intelligence Act ^[3]. The two actions therefore fell on the same calendar date, one year apart. The second bill's title describes it as a transparency measure aimed at frontier artificial intelligence — the term usually used for the most capable models at the leading edge of the field — rather than at AI in general.

Where this sits in his record

For readers who follow AI governance, these two decisions are the most relevant part of Newsom's record: a refusal to sign one bill aimed at frontier models, and a signature on a transparency law for frontier AI ^[2][3]. Read together, they show a governor engaging with the detail of how such systems should be treated in law, rather than treating all AI legislation the same way. The rest of his career runs through local government and business: a hospitality company built from a single wine shop, a seat on a city commission, a term on the board of supervisors, a city hall, and then the governorship of California ^[1].