Los Angeles — Rick Caruso, billionaire developer and underdog candidate for Los Angeles mayor, is mounting what might become the city’s largest-ever voter-turnout operation to try to defeat U.S. Rep. Karen Bass, who could be the first Black woman to lead the nation’s second-most-populous city.

Caruso is deploying several hundred paid canvassers and droves of volunteers to knock on doors, make phone calls and send texts and emails. Their targets are identified by campaign staff who rely on demographic research and polling to ferret out potential supporters among undecided Latinos, Asians and independents.

Of particular interest are people who sat out the June primary when Bass topped the field and outdistanced Caruso by 7 points, setting up a runoff.

Latinos make up about half the city’s population of about 4 million and they tilted toward Caruso in the primary, but can be inconsistent voters. Bass has been fighting for their votes, too, and has lined up endorsements including former Mayor Antonio Villaraigosa, City Council President Nury Martinez and labor leader Dolores Huerta.

Longtime Democratic consultant Roy Behr sees an opening for Caruso if he can win over enough voters who would otherwise have skipped the election. The outcome is “really dependent on both the turnout and the choices of Latino voters,” Behr said.

Consultant Dveen Babaian, who oversees Caruso’s paid canvassers, said in lower-income neighborhoods typically overlooked by campaigns “our door knocks are the first door knocks some of these voters have ever gotten.”

“This campaign will be won by engaging marginalized communities,” Babaian said.

On a recent afternoon in a heavily Latino neighborhood of modest homes in the city’s San Fernando Valley, a Caruso canvasser was knocking on doors and distributing flyers in English and Spanish.

The results were mixed. At some homes no one came to the door, but she was able to get others to pledge support for Caruso and agree to post yard signs.

In a conversation that jumped from English to Spanish, one woman said she was supporting Caruso because of frustration with high crime.

“I don’t believe that he is a Democrat,” she said of Caruso. “But I don’t care if you are going to do something.”

Caruso, in his first race for elected office, was a longtime Republican who switched and became a Democrat near the deadline to enter the race in a city where the GOP is virtually invisible.

He’s tapped into his estimated $5.3 billion fortune to build a $60 million war chest, most of it his own money, an amount that easily eclipses fundraising by all candidates in the previous three mayoral races.

Despite the financial advantage, even his internal polling shows he’s trailing.

Time is running out and the race has taken on an increasingly hostile tone as mail-in ballots go out for an election that concludes Nov. 8.

“It’s not the power of the money, it’s the power of the people,” Bass, a lifelong Angeleno and former state Assembly speaker, told cheering supporters at a recent outdoor rally.

The contours of the race have been set for months: finding solutions for the long-running homeless crisis, rising crime and runaway rents and housing prices.

The centrist Caruso, the son of Italian immigrants, is testing if the famously liberal city might swing to the political right for the first time in decades. He’s promising to expand the police department and quickly get homeless encampments off the streets.

The progressive Bass has positioned herself as a coalition-builder and emerged as the Democratic establishment pick, with her supporters including President Joe Biden and Vice President Kamala Harris, a former California U.S. senator and attorney general.

The winner will replace outgoing two-term Democratic Mayor Eric Garcetti, who has been largely absent in the contest. His nomination to become U.S. ambassador to India — made by Biden more than a year ago — appears stalled in the Senate over sexual harassment allegations against a former Garcetti top adviser.

Bass, who was on Biden’s short list for vice president, has been sharpening her attacks on Caruso, lampooning his decision to become a Democrat. She calls the campaign “a fight for the soul of our city,” echoing a line Biden used against then-President Donald Trump.

She also is underlining donations he has made to candidates who oppose abortion rights, including congressional Republican leaders Mitch McConnell and Kevin McCarthy. Caruso says he’s a supporter of reproductive rights.

Along with her own campaign infrastructure, she’s counting on the support of powerful labor unions that are working to turn out voters for her.

Bass “is actively reaching out to pro-choice Democrats,” campaign spokeswoman Sarah Leonard Sheahan said.

At the rally, a long line of speakers described Bass as the only authentic Democrat on the ballot and the only one with an unquestioned record defending reproductive rights.

In the crowd, Bass supporter Jennifer Yi, a Democrat who works on homeless initiatives at United Way of Greater Los Angeles, recoiled at Caruso’s campaign spending.

“I think he is trying to buy Los Angeles,” Yi said.

Caruso has resumed relentless TV and digital advertising, which include attempts to raise doubts about Bass’ character.

Bass has faced questions over a roughly $100,000, full-tuition scholarship she received from the University of Southern California’s social work program.

Last October, a longtime Bass friend, suspended City Councilman Mark Ridley-Thomas, and a former USC dean were charged with a bribery scheme in which Ridley-Thomas promised to steer millions of dollars in contracts to the school if his son got a scholarship and a teaching job. The former dean has pleaded guilty.

Federal prosecutors have said Bass is not a target of their investigation. But the Los Angeles Times reported in September that prosecutors said Bass’ scholarship and her dealings with USC are “critical” to their case.

Caruso said he was “troubled” and warned Bass would bring “corruption” to City Hall. Bass has said the case “has nothing to do with me.”