Reading Time: 5 minutes

Update, June 8, 2016, 8:17 a.m.: Hillary Clinton defeated Bernie Sanders in the Democrats’ California primary and laid claim to her party’s nomination. Sanders, who will meet Thursday with President Barack Obama, vowed to fight on.

Bernie Sanders left it all in California.

Even with rival Hillary Clinton on the precipice of securing the Democratic presidential nomination, Sanders burned through $2.2 million on advertising ahead of today’s California primary, according to data provided to the Center for Public Integrity by The Tracking Firm, a nonpartisan media tracking company.

Sanders’ spending eclipsed that of Clinton, who spent about $1.4 million on TV and radio advertising in California alone.

The competitive, delegate-rich California primary arrives hours after the Associated Press declared Clinton the presumptive nominee, meaning that she has earned enough delegates to clinch the nomination.

This count includes superdelegates: free agents — often party leaders — who vote for their favored candidate at July’s Democratic convention in Philadelphia.

Sanders’ ad flurry included about 2,800 TV ads targeting California voters in the weeks leading up to the primary, according to an analysis of data provided by Kantar Media/CMAG, a firm that monitors advertising on broadcast television and national — but not local — cable.

Clinton’s campaign aired nearly 3,000 ads in California during the same time frame.

Such a concerted effort in California makes sense: delegates there make up about one-fifth of the total 2,383 needed to secure the nomination.

And Sanders’ ad spending is indicative of how he isn’t quite ready to quit the campaign.

“Our job from now until the convention is to convince those superdelegates that Bernie is by far the strongest candidate against Donald Trump,” Sanders spokesperson Michael Briggs said in a statement on Monday.

Sanders’ entered May with about $5.8 million cash on hand, meaning his California ad spending represented a significant portion of his campaign’s cash reserve.

But even with all eyes on California, ad spending wasn’t overwhelming, said Ken Goldstein, a University of San Francisco politics professor who studies political advertising.

“California, it is a TV state, and neither Sanders or Clinton were not up at levels you would see in a competitive, engaged race,” Goldstein said.

Despite all but winning the Democratic nomination, Clinton’s California primary performance still matters.

A poor showing would feed the perception among some Democrats that she’s less likely than Sanders to defeat Donald Trump, the presumptive Republican nominee.

Clinton’s spending on advertising in California more than tripled going into June — perhaps a reaction to Sanders inching closer to Clinton in the polls. From May 24 to May 30, she spent $254,298. Then from May 31 to June 6, her spending increased to $952,327, according to The Tracking Firm.

Meanwhile, Sanders’ continued viability as a candidate — already minimal — hinges on California.

If he loses in California to Clinton, his hope of convincing hundreds of pro-Clinton superdelegates to flip their allegiance slips from remote to implausible.

Still, advertising is not a silver bullet for either candidate in California, and hasn’t been throughout the presidential primary, Goldstein said.

“Advertising has an impact at the margin,” Goldstein said. “At the end of the day, it didn’t lose the race for Bernie Sanders and it didn’t win the race for Hillary Clinton.”

Beyond California, Sanders and Clinton aired less than 400 ads in New Mexico, according to Kantar Media/CMAG, while forgoing TV advertising entirely in the four other states — New Jersey, Montana, North Dakota and South Dakota — conducting primaries today.

While Sanders continues his moonshot endeavor to become the Democratic nominee, Clinton operatives are already operating as if the former senator and secretary of state is Trump’s general election opponent.

Pro-Clinton super PAC Priorities USA Action is blanketing Florida, Nevada, Ohio, Tennessee and Virginia with TV ads, Kantar Media/CMAG data indicates. All of these states are likely swing states that could determine the outcome of the 2016 presidential contest.

The latest Priorities USA Action TV ad attacks Trump for mocking a New York Times’ reporter with a physical disability. (Trump denies he did.) The scathing 60-second spot features Chris and Lauren Glaros, parents who talk about their young daughter who was born with spina bifida.

“When I saw Donald Trump mock somebody with a disability, it showed me his soul. It showed me his heart,” Chris Glaros said in the ad. “I didn’t like what I saw.”

The anti-Trump TV ads are just beginning. Priorities USA Action, fueled by an elite group of liberal megadonors and even some “dark money” nonprofits, had about $46.7 million on hand heading into June, according to federal disclosures.

That’s on top of more than $130 million in TV and digital ads reserved starting this week after today’s primaries.

Priorities USA Action is a super PAC, meaning it can raise and spend unlimited amounts of money. Until this point, such outside groups aligned with Democrats have largely stayed on the sidelines, with the Clinton and Sanders campaigns themselves sponsoring most primary season political ads.

But Priorities USA Action is changing this dynamic, and is joined by NextGen California Action Fund, a super PAC founded by billionaire environmentalist Tom Steyer.

So far, the environmentally-focused super PAC has spent roughly $1.4 million on advertising in California — mostly get-out-the-vote ads that also target Trump.

Michael Beckel and Chris Zubak-Skees contributed to this report

This story was co-published with TIME.


Help support this work

Public Integrity doesn’t have paywalls and doesn’t accept advertising so that our investigative reporting can have the widest possible impact on addressing inequality in the U.S. Our work is possible thanks to support from people like you.

Cady Zuvich worked as a Center for Public Integrity reporting fellow from 2015 to 2016.