Traditional polling puts San Jose Mayor Matt Mahan toward the back of the pack in the race for California governor. But online gambling markets are betting bigger on his success.
While polls by Emerson College, UC Berkeley and the Public Policy Institute of California have all put Mahan under 5% favorability in the race, the largest betting pools on Kalshi and Polymarket have put him above bigger names such as former Congresswoman Katie Porter and billionaire Tom Steyer. That’s despite the fact that Steyer and Porter have fared better than Mahan in polls.
On Friday afternoon, Mahan’s odds reached 13% on a $4 million governor’s race betting pool on Kalshi, ranking him higher than Steyer at 10%, former Fox News host Steve Hilton at 8% and Porter at 3%. Compare that to traditional polling by Emerson College, where survey respondents gave Mahan a 3.2% favorability rating while Steyer got 11%, Hilton got 13% and Porter got 8.4%
A $1.5 million betting pool on Polymarket also has Mahan’s odds at 8% on Friday. Betters ranked Mahan’s odds above Porter at 5% and Riverside County Sheriff Chad Bianco at 4%, while the Emerson College poll puts the Republican candidate above Mahan at 11% favorability. Candidates’ positions on the betting sites fluctuate daily.
Representatives for Mahan’s campaign did not respond to requests for comment.
A $4 million Kalshi betting pool puts Mahan’s odds at 13% in the governor’s race as of March 13, 2026. Screenshot of Kalshi website.
While neither betting pool puts Mahan in the top two spots, they signal a collision of differing political prediction industries.
The Emerson, Berkeley and Public Policy Institute polls are scientific. They capture political opinions at one moment in time, surveying sample sizes that range between 500 and 1,600 respondents with a roughly 3% margin of error.
Favorability trends on online betting markets are shaped differently. The sample size depends on how many traders buy in — and can affect the direction of candidates’ odds. And as traders try to win money, experts say they’re more likely to bet on someone they believe has the best shot at winning, not someone they like or would vote for themselves.
“Politics has always been about the horse race — Who’s going to win? That’s the sexy thing in politics,” Mindy Romero, a political sociologist and founder of the Center for Inclusive Democracy at the University of Southern California, told San José Spotlight. “Online betting is just another type of horse race.”
Polling’s purpose is generally understood to be for public consumption, Romero said. And while not all polling is statistically sound or trustworthy, the practice has a reputation for being academic and unbiased.
“Online betting platforms are not scientific samples,” Romero said.
She added she doesn’t believe the online betting markets will immediately influence the governor’s race, since it’s still early and the betting trends aren’t widely publicized. Though in recent months, these betting sites have tried to puncture mainstream punditry. In December, Kalshi inked a partnership with CNN as the national news network’s official prediction market partner.
“I would assume, like anyone, they want to get more eyes on what they’re doing because they want more people placing bets. That’s good for business,” Romero said. “But we have to question what their motivations are for getting involved in politics.”
While Mahan’s odds have trended downward on both prediction markets this year, they surged as high as 36% on Polymarket on Jan. 29 — the day he entered the race — and 33% on Kalshi on Jan. 30.
“Polls tell us where an election stands today, while betting markets tell you where those who place bets think the race will end up,” Spencer Kimball, director of polling at Emerson College, told San José Spotlight. “These bets can be based on the polls, finance and general name recognition. Another notable difference is that surveys are of voters living in the state, whereas anyone can place a bet on an election.”
Forecasting elections
Jack Such, a spokesperson for Kalshi, agrees that polls and prediction markets measure different things. Comparing the two is like comparing apples to oranges, he said.
“Mahan being at 13% on Kalshi while polling at 5% isn’t necessarily reflective of him being overpriced relative to his polling,” Such told San José Spotlight. “Mahan ‘Yes’ traders likely believe that his support, including presumably his polling numbers, will increase over the next months.”
Such maintains prediction markets have become the “single most accurate method” for forecasting future events such as elections. He argues polls are a “very important complement” to prediction markets and help traders price outcomes.
“But (they) are ultimately less successful at forecasting eventual winners due to markets’ ability to harness the wisdom of the crowd and incentivize accurate probabilities through financial stake,” he said.
Sacramento-based Democratic strategist Steven Maviglio said prediction markets are likely more favorable to Mahan because the people who participate in prediction markets are more tech savvy than voters at large. Mahan’s gubernatorial campaign has garnered massive fundraising support from Silicon Valley’s billionaire tech elite.
“Voters in the June primary tend to be older, whiter and richer than voters in November and I don’t think they show up as predominantly in those markets as they do in polling,” Maviglio told San José Spotlight.
Maviglio has been critical of the traditional polling conducted in the race. He points to the Public Policy Institute of California poll, which found 48% of likely voters haven’t been following the race too closely.
“To me this race is still super wide open. I think (Mahan) is one of the candidates with the most room to grow because his campaign is relatively new and the advertising literally has just started,” Mavilgio said. “He is one of three candidates now that has any kind of on-air presence. The money is certainly going to boost his numbers over the long term.”
California Democratic Party Chair Rusty Hicks has been urging straggler blue candidates to drop out of the race for fear of Republicans taking the top two spots in the primary, after none of the candidates won the Democratic Party endorsement at the San Francisco convention last month. On Tuesday, the party announced plans to launch a large-sample statewide polling project aimed at providing a consistent picture of voter preferences to nudge more candidates out of the race.
Maviglio doesn’t think candidates should heed those calls.
“I think the voters should decide — not flawed pollsters and party bosses,” Maviglio said.
Contact Brandon Pho at [email protected] or @brandonphooo on X.
