Two candidates are running for Solano County’s District 4 Board of Supervisors seat representing northern parts of the county.
Vacaville Mayor John Carli and Vacaville City Councilmember Michael Silva moved to a runoff to represent District 4 after a close race in the June primary, with Silva ahead by a few percentage points.
The seat is currently held by John Vasquez, who was elected in 2022 and announced earlier this year that he would not seek re-election after receiving a stomach cancer diagnosis in 2025.
District 4 has around 96,000 residents, according to county data, and encompasses Dixon and parts of Vacaville. Solano County faces a projected deficit of $36.6 million in the 2026-27 fiscal year, compounded by the closure of several major employers, including the Anheuser-Busch brewery and the Valero Benicia Refinery. In the aftermath, jobs and economic development are priorities for county supervisors.
Michael Silva
Silva, elected to the City Council in 2020, grew up in Vacaville in a working-class agriculture family. He is a professor of biotechnology at Solano Community College.
His campaign states that he is a “people-first” leader and an advocate for affordable housing.
Silva is endorsed by a long list of local organizations, including the Solano County Democratic Central Committee, the Solano County Farm Bureau, labor groups, environmental groups, U.S. Rep. John Garamendi, D-Fairfield, and state Sen. Christopher Cabaldon, a Democrat from Napa.
Silva has raised $236,105 this year, much of it from labor organizations, farmers and Solano County District 3 Supervisor Wanda Williams’ campaign.
John Carli
Carli is a retired Vacaville police officer and police chief and was elected mayor in 2022. He boasts endorsements from Vasquez, Solano County District Attorney Krishna Abrams and several law enforcement groups. Carli’s campaign is focused on public safety and economic growth for the county. According to filings, he has raised around $225,530, much of it from agriculture professionals and construction groups.
Carli has pledged support for a plan to rezone hundreds of acres of land in southern Solano County to accommodate a massive shipbuilding project. The plan was pitched by the people behind billionaire-backed real estate venture California Forever, which seeks to develop a utopian new city neighboring Vacaville.
Solano County supervisors issued a blow to the project in August when they voted against passing legislation that would push the shipyard plan forward.
Last year, Carli and Silva went toe to toe over a proclamation to declare the month of June LGBTQ+ Pride Month during a June 10, 2025 City Council meeting. Silva voted in favor of the proclamation while Carli dissented. The proclamation passed narrowly.