Chula Vista's Chavez to run for county supervisor, kicking off race for institutional support

Driving the news: Chula Vista Councilmember Carolina Chavez confirmed to Axios Thursday she was joining the race, the third major Democratic elected to do so, joining San Diego Councilmember Vivian Moreno and Imperial Beach Mayor Paloma Aguirre.

• Chula Vista Mayor John McCann, a Republican, also told Voice of San Diego that he's considering a run, and is widely expected to join the field.

Between the lines: The board of supervisors have not called a special election yet, and procedurally still need to decide to do so, rather than appointing a replacement.

• But the rush by candidates to preemptively jump into the race has made the decision to call a special election a foregone conclusion, since Vargas' departure leaves a board evenly split with two Democrats and two Republicans.
• It will start with an open primary, in which the top two vote getters advance to a general election runoff, as long as no candidate breaks 50%.
• If McCann is the only Republican on the ballot, he'd be an odds-on-favorite to make the runoff, with multiple Democrats battling for the other spot.

What we're watching: With three Democrats running, the rush for support from major institutional players who have the political and financial influence to sway the outcome is now underway.

• An endorsement from the county Democratic Party could unlock significant resources that aren't subject to county campaign spending limits. But to get the endorsement, a candidate needs to secure 60% support from the party's central committee — a tall order with three candidates.

Without a party endorsement, backing from the county's largest labor unions will be even more critical than usual.

• Three candidates dividing support would make it harder for any one candidate to secure an endorsement from the powerful San Diego County Labor Council.

Zoom in: Support from individual labor groups could become critical.

• SEIU 221, which represents 10,000 county workers, and United Domestic Workers/AFSCME Local 3930 are active in county business and elections — they were major supporters of Supervisor Monica Montgomery Steppe's 2023 special election win, and Supervisor Terra Lawson-Remer's reelection win last year.
• Aguirre has a relationship with SEIU because the union also represents city workers in Imperial Beach and she's met with them in recent months to discuss the cross-border sewage crisis and has publicly advocated for their causes.

• Moreno won her first council race without labor support, but has a solid relationship with city workers and LiUNA Local 89, a construction union.
• Chavez has backed labor-supported policies in Chula Vista, but a vote to appoint a councilmember last year put her between unions who disagreed on that decision.

The intrigue: Developers, led by the Building Industry Association, could be a wild card in the race.

• Moreno has championed pro-development issues on the city council, but the BIA has historically been part of the county's conservative establishment, and McCann has a good relationship with the group.
• After Moreno won her 2018 race also without party support, right-of-center figures, including prominent developers, emerged to help her pay off her campaign debt.

By the numbers: County supervisor districts are huge. There are more than 370,000 registered voters in the South County District 1 seat, and nearly half of those are Democrats while just more than 80,000 are Republicans.

• Chula Vista, by comparison, has just under 175,000 registered voters, Imperial Beach has just over 14,000 and Moreno's District 8 seat in San Diego has nearly 85,000 registered voters.
• But in the low-turnout scenario expected during an off-cycle special election, the Democratic advantage could narrow.

Editor's note: This story has been updated with new information throughout.