When the Bernie Sanders-aligned Our Revolution endorsed Tom Steyer in California's governor's race, the irony of a progressive group founded on an anti-billionaire ethos backing a multibillionaire was not lost on its leader.

"If you had asked me a year ago, 'Oh, are you going to endorse a billionaire for anything? I think that would have been highly unlikely," said Joseph Geevarghese, Our Revolution's executive director. But Geevarghese said he had been impressed with Steyer's policy platform and engagement with liberal groups in the state. "The most energizing and ideologically aligned candidate just happens to be a billionaire," he said.

The unexpected alliance between progressives and Steyer — a hedge fund founder who has faced criticism for past investments in controversial spaces like private prisons — has helped vault him into the top tier of a California governor's race that lacks a clear favorite one month out from the all-party primary. Despite initial skepticism from liberal groups and politicians, Steyer managed to stay in the conversation with his consistent push for progressive priorities, including single-payer health care, taxing oil company profits and a billionaire tax likely to appear on the ballot this fall.

Former Rep. Eric Swalwell's exit from the crowded race last month and the struggles of other progressive candidates, including former Rep. Katie Porter backed by Sen. Elizabeth Warren, helped clear a lane for Steyer as he pumped more than $120 million of his own money into his campaign.

What the Right Is Saying

Critics of Steyer's progressive coalition point to the source of his wealth as evidence he cannot be trusted to fight for working-class Californians.

"Steyer made his billions off of investments in Big Oil, Wall Street, and private prisons — the very industries that Katie's spent her entire career holding accountable. Katie has consistently fought for disenfranchised Californians, while Steyer's fought only for himself," said Peter Opitz, a Porter campaign spokesperson.

Porter has been endorsed by prominent progressive elected officials including Warren, who appeared in a campaign ad released Friday, Rep. Robert Garcia, D-Calif., and the group End Citizens United.

Progressives also offered criticism of former Health and Human Services Secretary Xavier Becerra, who has seen his standing in polls rise following Swalwell's exit. "I get very bristled by the fact that people are trying to pretend that he's something he's not. He has never on the campaign trail even claimed to be progressive," Lee said.

Lee and others have criticized Becerra for his role in handling the migrant crisis during his tenure in the Biden administration, for refusing to release certain police records related to officers who used deadly force when he was California's attorney general, and for taking campaign contributions from Chevron. A Becerra campaign spokesperson did not respond to questions from NBC News.

What the Left Is Saying

Progressive groups that endorsed Steyer acknowledged the paradox but said they were prioritizing policy alignment over personal wealth.

"But a lot of our work has to do with holding corporations and the wealthy accountable — so in some ways, we feel like it is a good thing that voters and people are approaching Tom Steyer in this race with that sort of skepticism and holding him to account," said Irene Kao, executive director of Courage California, which endorsed Steyer in April. "But again, it is really important for people to be really wary about the wealthy, how they generated their wealth and what they do with it."

Democratic state Rep. Alex Lee, chair of the California Legislative Progressive Caucus, was one of the first state lawmakers to endorse Steyer in February. "I'm very sympathetic to voters who are skeptical of voting for a billionaire," he said. But as the field became clearer in recent months, Lee felt Steyer had firmly taken over the progressive lane among Democrats. "Frankly, look at the other options," Lee said.

Steyer has noted that his hedge fund sold its holdings in the private prison space and that he exited the fund itself in 2012. He has apologized for the investment too, calling it a "mistake" and has run ads responding to the criticism.

Following his career at Farallon Capital, Steyer emerged as an outspoken climate advocate and founded NextGen America, a progressive PAC working on climate, health care and reproductive rights. His unsuccessful 2020 presidential run focused heavily on climate issues.

What the Numbers Show

A CBS News/YouGov survey released April 20 found that Steyer had the support of 15% of registered California voters. Becerra was at 13%, Porter was at 9%, and no other Democrat had above 4%. The two prominent Republicans in the race — former Fox News host Steve Hilton, who is endorsed by President Donald Trump, led all candidates with 16%, while Riverside County Sheriff Chad Bianco got 10%. All top-polling candidates fell within the survey's margin of error.

The California Democratic Party tracking poll released April 20 found that Porter was still earning the most support among self-identified progressive voters despite her struggles in the race.

Steyer has invested more than $120 million of his own money into his campaign, a sum that dwarfs all other candidates. Candidates from all parties will appear on the same June 2 primary ballot, with the top two vote-getters advancing to the November general election. Ballots go out for early voting this weekend.

The Bottom Line

Democrats have been desperate to unite behind one candidate to avoid an outcome of two Republicans emerging from the primary but have struggled to do so. Steyer's alliance with progressive groups represents a calculated bet by both sides: billionaires willing to fund progressive causes can earn credibility with left-leaning voters, while progressive organizations gain access to a campaign apparatus funded at levels traditional donors cannot match.

Porter's difficulties illustrate how internal campaign dynamics and candidate temperament questions can undermine even well-resourced campaigns with strong ideological credentials. The June 2 primary remains one month away, leaving time for the race to shift further before ballots are counted.