Who are the independent groups pouring money into California's U.S. Senate race?

The four leading candidates in the battle for California’s hotly contested U.S. Senate seat have spent a combined $69 million wooing voters before the March5 primary, and independent Super PACS have pumped more than $16 million of their own into influencing the outcome.

Wealthy donors, including philanthropists and environmental lawyers, supporters of Israel and cryptocurrency businesses, are behind the race’s super PACS — political action committees that can raise unlimited money for or against candidates and operate independently from their campaigns.

And their influence has become a flashpoint in the contest between Democratic Reps. Adam Schiff of Burbank, Katie Porter of Irvine, Barbara Lee of Oakland, and Republican former Dodgers star Steve Garvey.

Though PAC spending in the race isn’t “huge,” it’s “noteworthy” in a race with three Democrats splitting their vote and could tip the balance in deciding who advances past the primary, Sonoma State University

political science professor David Mccuan said.

Schiff has consistently led in polling and fundraising, and the overwhelming majority of Super PAC spending has gone toward opposing his top rivals, Garvey and Porter, who’ve been battling for second place in several polls while Lee has trailed in fourth place. Under California rules, the top two finishers in the primary will compete in a November runoff regardless of party affiliation.

Porter has been outspoken about the influence of PACS she says are helping Schiff.

“Super PACS routinely meddle in races, and frankly they often get their way,” she told supporters in a recent fundraising pitch. “Their prize is a politician who is beholden to them for decades to come.”

The largest share of Super PAC spending — a staggering $7.5 million — has gone toward ads opposing Garvey, a former first baseman for the Dodgers and San Diego Padres.

The pieces against Garvey are funded by Standing Strong PAC. Its website and campaign filings give little indication of its interests, and it didn’t respond to a request for comment, though it’s been reported to be run by Schiff allies. Top donors include developer Joseph W. Kaempfer, entrepreneur Eric Laufer and a carpenters union.

The Standing Strong ads note Garvey twice voted for former President Donald Trump, the Republican presidential front-runner who is popular with California Republicans but unpopular among state voters overall, and say he’s a threat to “tip the Senate” Republican and “advance Trump’s agenda.”

Porter has argued the ads, which echo anti-garvey ads from Schiff’s own campaign coffers, are a “cynical” Schiff strategy to give the former ballplayer free publicity and boost him to a second-place primary finish. That would give Schiff an easier November opponent in deep blue California.

Schiff’s campaign has declined comment other than to note Porter has done likewise with ads opposing lesser-known Republican Eric Early, who’s polling far behind her in the Senate race. She also targeted leading Republican Mimi Walters when she ran for Congress in 2018 against three other Democrats.

Garvey’s campaign argues Schiff isn’t helping him but fending threat.

“It might be that Schiff is more concerned with Garvey getting first than Katie getting second,” Garvey campaign spokesman Matt Shupe said.

The second-largest amount of independent spending in the race has come from pro-cryptocurrency Super PAC Fairshake, which has spent a massive $6.8 million on ads opposing Porter.

Fairshake describes itself as supporting candidates committed to “providing blockchain innovators the ability to develop their networks under a clearer regulatory and legal framework.” Its biggest donors include blockchain company Ripple, cryptocurrency platform Coinbase, and Silicon Valley venture capital firm AH Capital Management.

Fairshake ads say that while Porter “claims not to take corporate PAC money” she “takes campaign cash directly from Big Pharma, Big Oil and the Big Bank executives” totaling “more than $100,000.” It cites contributions of $500 from Spectrum Pharmaceuticals, $2,000 from Wood Oil Co. and $2,900 from Royal Business Bank.

Porter has denounced off a the ads as “funded by shady crypto billionaires” and pointed to a Sacramento Bee article calling the ads “mostly false” because the cited donations are from companies it argued aren’t “big.”

The next big chunk of Super PAC spending came from She Speaks for Me, set up to support Lee’s candidacy and principally funded by Quinn Delaney, founder of the Akonadi Foundation, which supports East Bay social change movements, and Patty Quillin, philanthropist wife of Netflix CEO Reed Hastings.

She Speaks for Me raised nearly $1.5 million and spent most of it last year, with its last expenditure on digital and TV ads in mid-january. But polling and fundraising suggest the “courage” ads telling Lee’s story of growing up poor and Black, confronting racism and marital abuse and casting the sole vote against the U.S. military action in Afghanistan after the 9/11 terrorist attacks, haven’t helped her rise above fourth place.

Porter has benefited some from an Oaklandbased Super PAC of supporters called Ovrsite, which reported spending $490,000 on her behalf for ads touting her as a corporate antagonist.

“Big corporate interests don’t want Democrat Katie Porter as our next U.S. Senator,” the ads say, showing snippets of her grilling company executives at congressional hearings.

Campaign filings show Ovrsite’s principal funder is Gerald Singleton and his Singleton Schreiber law firm, where he has specialized in representing claims over wildfire losses and harms from “forever chemicals” and toxic chemicals from the oil and gas industry.

A couple of independent expenditures have funded ads promoting Schiff, though they total only $20,700 worth.

More than $16,000 of that was for print ads funded by DMFI PAC. It seeks to elect pro-israel Democrats to Congress, and Schiff, who is Jewish, has voiced strong support for Israel’s response to the Oct. 7 Hamas terrorist attack.

Another PAC, Blue Wave America, paid a little over $4,000 for email ads and messages supporting Schiff. It’s a group that promotes Democrats in largely rightleaning rural areas whose top donors contributed $1,000 to $5,000 each.