The race for California governor has become a showcase of how campaign finance can reshape political contests. Outside groups, corporate interests and wealthy individuals have injected tens to hundreds of millions of dollars into the primary, directing advertising, political action committee spending and independent expenditures toward or against specific contenders.
Those financial flows both signal where establishment and private power see leverage and affect what voters hear on screens, radio and billboards. Below we unpack the main funding players, where their money has landed and what that has meant for individual campaigns.
Scale and scope of outside spending
Independent organizations that can accept unlimited contributions have reported roughly $79 million in spending so far, a sum that far outstrips what similar actors spent ahead of the 2018 primaries. This class of spending includes industry coalitions, union-backed committees and corporate-funded PACs, and it has driven unprecedented ad volumes and targeted outreach.
Major targets and backers
One of the clearest targets of that cash has been Tom Steyer. A coalition called California Is Not For Sale—underwritten by the state association of realtors, the California Chamber of Commerce, Pacific Gas & Electric and the state electrical workers union—has invested about $32 million in ads opposing him. These attacks emphasize Steyer’s plans to challenge utility monopolies and reform commercial property tax assessments, issues that threaten long-standing business interests.
At the same time, other outside groups have funneled about $13 million to support Xavier Becerra through PACs and allied committees. Donors to the largest pro-Becerra entities include Chevron, McDonald’s, DaVita, and California Resources Corp., each giving roughly $500,000. Technology and platform firms such as Meta and Airbnb have also contributed close to $1 million each, and health insurer Centene provided $100,000.
How individual campaigns have been affected
Steyer has spent heavily on his own behalf—far more than most rivals—and has used those funds to saturate media markets with advertising, hire influencers and deploy mobile billboards promoting his positions and critiquing opponents. His campaign’s outlays total approximately $213 million, a spend level that makes this the most expensive primary for California governor in state history. That total eclipses the high-profile 2010 primary spending by Meg Whitman, adjusted for context, and stands out as a defining feature of the current contest.
The rise and fall of a Silicon Valley-backed campaign
Another notable example is the late entry mayor from San José, who attracted sizeable backing from Silicon Valley investors and executives. Two independent committees, fueled by luxury donors such as Michael Moritz, Brian Singerman, Tony Xu, Scott Cook, Sergey Brin and Rick Caruso, spent nearly $22 million promoting him, while his campaign itself raised about $9 million. The effort aimed to champion efficiency-focused governance and fend off regulatory or tax pressures on the tech sector, but it struggled to overcome limited name recognition and failed to reach the significantly larger benchmarks donors expected.
One PAC even returned $1 million to Reed Hastings after fundraising fell short of ambitious targets, an acknowledgment that the broader donor coalition could not scale the operation sufficiently late in the cycle.
Union contributions, donor realignments and candidate dynamics
Labor groups and progressive unions have played a role too. The California Nurses Association and United Domestic Workers invested about $1.4 million in materials and digital outreach supporting Steyer. Conversely, outside committees spent about $1.8 million against Republican frontrunner Steve Hilton.
When Eric Swalwell exited the race amid controversy, many of his prior backers shifted their support to Becerra. Organizations that had backed Swalwell—like DaVita, the California Medical Association and the state professional firefighters association—pivoted quickly to back Becerra, helping consolidate establishment support. More than 500 small donors who had contributed to Swalwell later gave to Becerra as well.
Donor bases and geographic reach
Donation patterns reveal different strategies and constituencies. The Republican favorite, Steve Hilton, amassed the largest donor count—over 20,000 contributors—with a sizable share coming from outside California. Katie Porter, a progressive former congresswoman, gathered more than 15,000 donors and the highest share of out-of-state support, reflecting her national profile, though her fundraising pace flagged later in the campaign window.
These patterns illustrate the broader lesson: in modern statewide contests, money from both within and beyond state borders can determine not only the tone of the campaign but which messages reach voters most persistently.
What this means going forward
Large infusions from corporations, unions and wealthy individuals have already shifted the narrative and resource balance in this primary. The prominence of independent expenditures underlines how outside money can amplify or blunt candidates’ messages regardless of their own fundraising. Voters are therefore seeing a version of the contest heavily influenced by groups with specific policy interests—utilities, tech companies, medical providers and labor unions—each trying to tilt the outcome toward candidates aligned with their priorities.
As the primary continues, the relationship between spending and voter response will remain the key variable: sizable ad buys and targeted PAC campaigns can change visibility quickly, but they do not guarantee voter conversion. The final months will test whether record-setting expenditures translate into the electoral returns their backers seek.
