Voter engagement was slightly higher in the June primary election than in recent years’ primaries, with more San Diego County voters registering and casting a ballot, data from the County Registrar of Voters show.

Meanwhile the county’s election results, which still have yet to be certified, show where support for each of the most popular governor candidates was strongest.

Republican Steve Hilton, the single most popular candidate in the county, won more votes than any of his competitors in wide swaths of East and North County, and in many Democratic-leaning neighborhoods including La Jolla and Clairemont. Democratic establishment candidate Xavier Becerra was solid in South County, Escondido and San Marcos, while fellow-party and more progressive candidate Tom Steyer captured many parts of San Diego city proper.

But primary votes are still being counted in Riverside County for what many agree will be the biggest competitive race involving San Diego this November: the 48th Congressional district, a race that will help decide which party controls the House.

The county has finished counting all valid ballots from the June primary, but there are 5,600 mail ballots that need to be cured, meaning they have a missing or mismatched signature. That number is equivalent to less than 0.6% of total ballots.

The county is giving those voters a chance to correct their ballot signatures. After unresolved ballots are cured and counted, the county registrar says it will certify election results by the evening of July 2.

More voters registered

Voter registration was up this year from the last primary, data from the county registrar show. Two million San Diego County residents registered to vote, compared to 1.9 million in 2024.

Political party makeup in the county hasn’t changed much since two years ago.

Democrats still dominate the county overall, but their numbers declined slightly from 2024. About 40.5% of the county’s registered voters filed as Democrats for this primary, down from 41.4% in 2024.

Meanwhile 27.4% filed as Republicans, about the same as in 2024.

A quarter of voters declined to declare a party preference, which is up by half a percentage point from 2024.

San Diego County’s political makeup falls in line with national trends, said Carl Luna, director of the Institute for Civil Engagement at University of San Diego. Republicans dominate the rural and exurban communities of East and North County, while Democrats dominate urban neighborhoods and areas with more young people.

Higher, but uneven turnout

This year’s gubernatorial primary drew higher voter participation than recent similar elections.

About 42% of county registered voters cast a ballot, which is higher than the county’s turnout in each of the past three non-presidential primary elections.

Turnout is also up significantly from the presidential primary two years ago, when it was only about 37%.

Geographic disparities remain. Many of the county’s lowest turnout rates were in the urban cores of El Cajon, Escondido, Vista and San Marcos, as well as precincts in San Ysidro, City Heights, Southeast San Diego, National City, Nestor and western and southern Chula Vista. Precincts in those communities had turnout rates below 30%, and in some cases below 20%.

Those low turnout rates are largely to the Democrats’ disadvantage, as all of those areas lean Democratic.

Turnout tends to correlate with age, education levels and socioeconomic status, said Brian Adams, political science professor at San Diego State.

Primary elections consistently see far lower turnout than general elections. In the 2024 general election, county voter turnout was 76%.

“When you get lower voter-turnout elections, you get biases in who’s voting and who’s not voting. Historically that usually favored Republicans,” Adams said.

The real test that will decide the winners of competitive races in November is which party can turn out more voters, he said.

“Most voters already made up their mind which party they’re supporting. The actual number of persuadable voters is very small. Because of that, what really matters is turnout,” Adams said.

Democratic votes split for governor

In a candidate field that saw far more competition for Democrats than Republicans, GOP candidate Hilton was the single most popular governor candidate in the county, capturing about 30% of the vote.

Democratic votes were split between former Attorney General Becerra, who captured the second most votes in the county with 27%, and billionaire Steyer, who captured the third most at 21%.

Unlike Becerra and Steyer, Hilton didn’t suffer as much from a split vote with Republican Chad Bianco, who got 8% of the county total.

San Diego County favored Hilton more than California as a whole, which gave Hilton about 25% of the vote. San Diego County voters were also less likely than voters statewide to support Steyer or Bianco.

Hilton captured more votes than any other candidate in Republican-dominated areas of the county — the exurbs and rural areas of East County and North County. But he also did well in many parts that lean Democratic, including La Jolla, Point Loma, Del Mar Heights, Scripps Ranch, eastern Chula Vista and parts of Clairemont.

That’s largely because the Democratic vote was split between Becerra and Steyer. It may also be because voters who turn out for primaries have tended to skew more conservative than general elections, Adams said.

“Different people may be voting in November, so we’ll have to see how that plays out,” he said. “When you get lower voter-turnout elections, you get biases in who’s voting and who’s not voting.”

Steyer, the more progressive Democrat, captured the plurality of votes in several parts of San Diego city.

But Becerra remained the clear Democratic favorite in South County, in the urban cores of Escondido and San Marcos, as well as most of Vista and Oceanside. Luna said that reflects Latino support as well as support for a more traditional establishment candidate.

With Republicans Hilton and Bianco combining to capture only 35% of the vote statewide in the primary, Luna and Adams are expecting Becerra to be ushered in easily. The biggest competition out of San Diego County, they said, will be the 48th Congressional district race.

Thanks to last year’s redistricting, the historically Republican seat — which sits partly in Riverside County — is now competitive between the two big political parties.

Republican county Supervisor Jim Desmond will face off with San Diego Councilmember Marni Von Wilpert, a Democrat, for the seat.

In the primary, Desmond won 42% of the vote within San Diego County, while Von Wilpert captured 22% in a field crowded with Democrats. The one other Republican candidate in the primary, Kevin O’Neil, got 3%.

The fate of the seat could help determine party control of the House. “The only significant race is the 48th,” Luna said.