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 September 7, 2026.

County

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

This person is one of five supervisors who govern San Mateo County. They vote on the county budget. They also decide land use in unincorporated areas. They oversee county health, parks, and social service departments. This seat is a short term. It fills the rest of District 5's current term. The term ends at the county's next regular election.

San Mateo County's District 5 supervisor seat is on the ballot early. Supervisor David Canepa won a June election to be the county's next Assessor-County Clerk-Recorder. He is resigning from the board, so this seat is being filled early. Mark Nagales faces Juslyn Cabrera Manalo for it.

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 Manalo's 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 Vice Mayor of South San Francisco. They have served on that city's council since 2018. They represent District 2 there. They were the city's mayor in 2022. They are running for the seat David Canepa is leaving early.

Juslyn Cabrera Manalo

Juslyn Cabrera Manalo is a Daly City Councilmember. They were elected in 2016 and reelected in 2024. They were Daly City's mayor for one year starting in December 2023. They are running for the seat David Canepa is leaving early.

Your pick

A nonpartisan office: candidates do not run as Democrats or Republicans, and no party appears on the ballot.

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