High-stakes primary races taking place on Tuesday in California are expected to have major consequences for police reform, incarceration and the state’s growing homelessness crisis.

The most closely watched race is the mayor’s contest in Los Angeles, where voters are deciding between a tough-on-crime real estate developer, Rick Caruso, who has already poured nearly $40m of his own fortune into his primary campaign, and the former community organizer and Democratic congresswoman Karen Bass.

In San Francisco, the city’s progressive prosecutor, Chesa Boudin, is facing a recall election that could have a major impact on movements for criminal justice reform across the US.

Midway through a tense midterm elections year, the races are likely to serve as a litmus test for Democrats and progressives. Analysts are watching to see if the majority of voters in some of America’s most ostensibly liberal cities decide to reject attempts to reduce mass incarceration and address the stark racial disparities in the criminal justice system.

But one of the starkest takeaways so far is that voters simply are not very engaged in California’s primary election, despite multiple measures designed to make it easier for them to participate. Early turnout so far has been abysmal, even though every registered voter in California was mailed a ballot.

“Even if you make it extremely easy to vote, like in California, but the political culture, candidates and issues aren’t there, you aren’t going to increase the turnout,” political scientist Fernando Guerra said. “We have extreme generational issues, with homelessness and crime and the cost of housing, and I think we have the candidates. There’s a lack of political culture.”

Lower turnout is likely to be a particular challenge for “a lot of the young progressive candidates”, who might end up losing to an incumbent by a small margin of votes, Guerra said.

Voters in California and nationwide are concerned about gas prices and the cost of living. A recent poll found that only a third of Los Angeles voters approved of the city’s police department, a lower approval rating than in 1991, after the police beating of Rodney King, but that nearly half of voters surveyed wanted to increase the size of the force.

The role of the police in public safety is one of the key issues up and down the ballot, with younger progressive candidates who support defunding the police challenging older centrist Democrats in several Los Angeles city council races.

Bass, the former chair of the Congressional Black Caucus, supports police reform and a modest increase in Los Angeles police department staffing; Caruso has pledged to put an additional 1,500 officers on the street.

Both Bass and Caruso have promised to put an end to people sleeping on the street in Los Angeles. Caruso has expressed willingness to arrest unhoused people who refuse to move to a city-provided shelter bed, and has also praised an army camp for undocumented children at the Texas border as a good model for how to deal with the city’s homelessness crisis.

For some Los Angeles progressives, Bass’s more centrist positions on policing and homelessness have been a disappointment. Two years after George Floyd’s murder by police sparked worldwide protests, some activists see Bass’s endorsement of putting more police on the street as a step backwards.

“She’s losing the enthusiasm of folks on the left, and I think that is a miscalculation,” said Melina Abdullah, a co-founder of Black Lives Matter, Los Angeles, who endorsed Gina Viola, a local activist running to Bass’s left, for mayor.

Progressive groups in LA have also organized to oust the incumbent LA county sheriff, Alex Villanueva, who has been at the center of multiple scandals related to abuse and misconduct cases within the department. His critics, however, have not rallied behind one opponent among his eight challengers.

The role of massive personal fortunes in public elections has also become a central issue in California’s primary campaigns. The attempt to recall Boudin, a central figure in the movement to elect prosecutors who want to make the legal system less punitive and racist, is reportedly being funded by ultra-wealthy donors, many of them in the tech industry, including: Ron Conway, an early DoorDash investor; Garry Tan, an Instacart investor; and David Sacks, a former PayPal executive.

The result of the attempt to recall Boudin in San Francisco will “affect whether prosecutors elsewhere feel emboldened to take new approaches or whether they will perceive that as a political risk”, said Sandra Mayson, a University of Pennsylvania law professor.

Political spending on the Los Angeles mayoral primary has already topped $50m, with Caruso’s campaign spending more than $40m of that. Bass’s campaign has spent $3m, in contrast, and a local police union has spent a similar amount on advertisement opposing her candidacy.

On Friday, Elon Musk, one of the richest men in the world, tweeted his public endorsement of Caruso, who himself is ranked No 261 on Forbes’ list of richest Americans. “He’s awesome,” Musk wrote. “Executive competence is super-underrated in politics – we should care about that a lot more!”

Caruso, a real estate developer with an estimated net worth of $4bn, has used at least $38m of his own money to move to the front of a crowded non-partisan primary field, a number that has already broken every previous record for mayor’s races in Los Angeles, local experts said. The billionaire’s personal fortune has funded a barrage of attractive television ads and mailers touting his candidacy, even as Caruso has skipped some mayoral debates, and largely avoided engaging with the press or holding open public events.

Bass and then Caruso took an early lead in mayoral polls, leading other mayoral primary contenders to drop out of the race, though some, such as Kevin de Leon, a current city council member, fight on.

Heading into Tuesday, polls showed Bass and Caruso closely matched in terms of voter support, setting up the possibility that neither would surpass the 50% vote threshold needed to win outright. In that case, the top two candidates will advance to a runoff election in November, a result that is expected to generate millions more in political spending from Caruso and from Bass’s progressive backers in Hollywood.