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County · Statewide General Election

San Mateo County Board of Supervisors, District 5 (Short Term)

Draft candidate list — early preview until the state’s official list publishes on August 27, 2026.

This is one contest. Enter your address to see every race on your November ballot, and keep track of your picks.

On the ballot

This person is one of five supervisors governing San Mateo County: the county budget, land use in unincorporated areas, and county health, parks, and social-service departments. This particular seat is a short term -- it fills only the balance of District 5's current term, through the county's next regularly scheduled election.

San Mateo County's District 5 supervisor seat is on the ballot early: Supervisor David Canepa won election in June as the county's next Assessor-County Clerk-Recorder and filed a deferred resignation from the board, so the county consolidated a special election into this November's general. South San Francisco Vice Mayor Mark Nagales faces Daly City Councilmember Juslyn Cabrera Manalo for the seat.

Whoever wins takes a shortened term: this seat returns to the county's regular election cycle after this term ends, but until then this person sits on the 5-member Board of Supervisors that sets the county budget, oversees land use in unincorporated areas, and directs county health, parks, and social-service departments.

Both candidates already hold local council seats and lead with different lengths of tenure: Nagales points to eight years on South San Francisco's council, including a 2022 term as mayor; Manalo points to ten years on Daly City's council, including her own turn as mayor. The choice is less about ideology than about which sitting North County council leader voters want representing them at the county level.

Mark Nagales

Mark Nagales is the Vice Mayor of South San Francisco, representing District 2 on that city's council since 2018. He's running for the District 5 supervisor seat David Canepa is vacating early. He served as South San Francisco's mayor in 2022 and previously worked as Constituent Services Director for Congresswoman Jackie Speier, where he helped recover more than $5 million in veterans' benefits.

Strengths

Eight years on South San Francisco's council, a 2022 mayoral term, and prior experience as a Congressional aide -- exposure to two other levels of government before running for a third.

Trade-offs

His council seat is city-level; county government spans land use, health, and social services across a much larger area, and he has no supervisorial record to point to yet.

Keep in mind

His 2026 committee is active but has not yet filed a campaign-finance disclosure with the state, so there's no fundraising picture yet -- see Financial info below.

Juslyn Cabrera Manalo

Juslyn Cabrera Manalo is a Daly City Councilmember, first elected to that city's council in 2016 and reelected in 2024. She's running for the District 5 supervisor seat David Canepa is vacating early. She was chosen by her fellow councilmembers to serve as Daly City's mayor for a one-year term beginning December 2023, after previously serving as vice mayor.

Strengths

Ten years on Daly City's council, including a term as mayor chosen by her colleagues, plus current committee assignments representing the city on regional water-supply matters.

Trade-offs

Like Nagales, her elected experience is city-level, not county-level, and she has no supervisorial record to point to yet.

Keep in mind

Her 2026 committee is active but has not filed a disclosure yet -- see Financial info below. She's also registered a 'Manalo for Supervisor 2028' committee, consistent with this short term: whoever wins faces a full-term election in 2028 regardless.

Source review: Very strong (91/100) · 8 cited sources

Official records anchor this contest, with multiple sources checked.

  • smcacre.gov (opens in a new tab)San Mateo County ACRE (Assessor-County Clerk-Recorder-Elections) -- Roster of Candidates, Qualified Candidates Only, November 3, 2026 General Election (CFMR009), dated 2026-08-25: the county's own certified candidate list, confirming both District 5 (Short Term) candidates and their ballot designations, and that Board of Education Trustee Area 2 is the only one of three expiring county trustee areas flagged 'On Ballot: Yes'
  • rwcpulse.com (opens in a new tab)Redwood City Pulse -- "Supervisor Canepa replacement election set for Nov. 3 ballot" (July 10, 2026): the Board of Supervisors voted to consolidate the required special election with the November 3 general at Canepa's own request, 'to save the county money' and increase turnout; explains the elections-code trigger for a special election given the timing of his deferred resignation
  • smdailyjournal.com (opens in a new tab)San Mateo Daily Journal -- "Juslyn Manalo, Mark Nagales campaigns launch for District 5 supervisor seat" (Ana Mata, Aug. 10, 2026): staffed local reporting confirming both campaigns and independently corroborating that Supervisor David Canepa is leaving the board early to become the county's next elections officer, clerk, and assessor
  • smcgov.org (opens in a new tab)County of San Mateo -- Board of Supervisors page: the sitting 5-member board by district (Speier D1, Corzo D2 President, Mueller D3 Vice President, Gauthier D4, Canepa D5), confirming the board's size and that Canepa is the sitting District 5 supervisor as of this retrieval
  • ssfca.gov (opens in a new tab)City of South San Francisco -- official council biography for Vice Mayor Mark Nagales (District 2): grew up in South San Francisco, B.A. from SF State, prior aide to Rep. Jackie Speier (helped recover over $5 million in veterans' benefits), Parks and Recreation and Planning Commissioner before his 2018 council election, city mayor in 2022
  • dalycity.org (opens in a new tab)City of Daly City -- official pages for Councilmember Juslyn C. Manalo: current term expires November 2028, regional-agency representation (Bay Area Water Supply and Conservation Agency); a Dec. 12, 2023 city press release names her selection by fellow councilmembers as Mayor for a one-year term, and her own 2024 reelection filing states she was 'currently your Vice Mayor' and 'elected in 2016' -- reached via Google's cache after the city's own CivicEngage site returned an intermittent 404 on direct and re-tried navigation
  • cal-access.sos.ca.gov (opens in a new tab)California Secretary of State CAL-ACCESS -- "NAGALES FOR SUPERVISOR 2026; MARK" (Filer #1492502), status ACTIVE; no Form 460/461/450 electronically filed for the 2025-2026 cycle as of this retrieval. Filer search also surfaces four prior, terminated 'Nagales for City Council' committees (2013-2024)
  • cal-access.sos.ca.gov (opens in a new tab)California Secretary of State CAL-ACCESS -- "MANALO FOR SUPERVISOR 2026; JUSLYN" (Filer #1493016), status ACTIVE; no Form 460/461/450 electronically filed for the 2025-2026 cycle as of this retrieval. A separate, also-active "MANALO FOR SUPERVISOR 2028; JUSLYN" committee (#1480650) is registered too -- consistent with this seat's short term, since whoever wins in 2026 faces a regular election for a full term in 2028

Last updated August 31, 2026.