California's 10th congressional district
California's 10th congressional district is a congressional district in the San Francisco Bay Area U.S. state of California. It is currently represented by Democrat Mark DeSaulnier.
Since redistricting in 2022, the 10th district is mostly in Contra Costa County with a small portion in Alameda County. It includes the cities of Concord, Walnut Creek, Danville, San Ramon, Brentwood, and southern Antioch in Contra Costa County, and eastern Dublin in Alameda County. It was essentially the successor of the old 11th district.
The district previously included all of Stanislaus County and part of San Joaquin County. It was centered on Modesto. Cities in the district included Oakdale, Manteca, Modesto, Tracy, and Turlock.
History
Until 2012
Prior to redistricting by the California Citizens Redistricting Commission going into effect in 2012, the 10th district stretched from Livermore to Dixon and the outskirts of Vacaville. It consisted of portions of Alameda, Contra Costa, Sacramento, and Solano Counties.Following redistricting in 1992, the 10th district was based in the East Bay, and included parts of Alameda and Contra Costa counties. It received national attention in 1996 when Democrat Ellen Tauscher defeated incumbent Republican Bill Baker in what was considered an upset.In the 2002 redistricting of California, all seats were made safe for the parties of incumbent officeholders. The district boundaries were extended to include parts of Solano County, southwestern Sacramento County, eastern Contra Costa County and El Cerrito in western Contra Costa County. Although much of the suburban Tri-Valley region was shifted to the 11th congressional district, the city of Livermore remained in the 10th at Tauscher's request.
On June 26, 2009, Tauscher resigned her seat to be sworn in as Undersecretary of State for Arms Control and International Security. In the ensuing special election held on November 3, 2009, former Democratic Lieutenant Governor John Garamendi won the seat over Republican David Harmer 53.0% to 42.7%. Immediately following redistricting, Garamendi successfully ran for re-election in California's 3rd congressional district, which shares many municipalities with the 2002 version of the 10th district, but lies significantly northwest of the current 10th district.
2012 – 2022
The 10th congressional district starting with the election of 2012 and lasting through the election of 2020 included all of Stanislaus County and the southern portion of San Joaquin County.This went into effect in 2012, as the result of redistricting by the California Citizens Redistricting Commission. This version of the 10th included much of the core of the old 18th district, though the 18th also included a substantial portion of Stockton. It also shares much of the northwestern portion of the old 19th district.
Republican Jeff Denham transferred from the prior 19th district to the newer 10th. He held it for three terms until being defeated in 2018 by Democrat Josh Harder, who won reelection in 2020.
After 2022
The 10th district was redrawn in time for the 2022 election, being divided up between California's 5th congressional district, California's 9th congressional district, and California's 13th congressional district . The 2022 10th district incumbent Josh Harder was reelected and moved to the new version of California's 9th congressional district. The district has been represented since Jan 3, 2023 by Mark DeSaulnier.Voter registration statistics
The California secretary of state publishes reports on California voter registration on a regular basis. Before the 2018 primary election, they published a report dating May 21, 2018.| Date | Democratic | Republican | American Independent | Green | Libertarian | No Party Preference |
| May 21, 2018 | 127,878 | 117,900 | 10,011 | 959 | 2,484 | 70,251 |
Recent election results from statewide races
2023–2027 boundaries
2027–2033 boundaries
Composition
Under the 2020 redistricting, California's 10th congressional district is located in the San Francisco Bay Area, encompassing most of Contra Costa County, and part of Alameda County. The area in Contra Costa County includes the south sides of the cities of Antioch and Martinez; the cities of Concord, Brentwood, Oakley, Pleasant Hill, Clayton, Walnut Creek, Lafayette, Orinda, and San Ramon; the towns of Danville and Moraga; and the census-designated places Norris Canyon, Camino Tassajara, Blackhawk, Diablo, Alamo, Castle Hill, Saranap, Acalanes Ridge, San Miguel, North Gate, Shell Ridge, Contra Costa Centre, Reliez Valley, Alhambra Valley, Mountain View, Vine Hill, Pacheco, Clyde, Knightsen, and Bethel Island. The area in Alameda County includes the eastern portion of the city of Dublin.Contra Costa County is split between this district, the 8th district, and the 9th district. The northern border is partitioned by Grizzly Peak Blvd, Seaview Trail, Camino Pablo, Bear Creek Rd, San Pablo Creek, Bear Creek, Brianes Reservoir, Burlington Northern Santa Fe, Highway 4, Alhambra Ave, Pacheco Blvd, Grandview Ave, Central Ave, Imhoff Dr, Bares Ave, Mount Diablo Creek, Union Pacific, Contra Costa Canal, 4WD Rd, Bailey Rd, James Donlon Blvd, Cambridge Dr, Reseda Way, S Royal links Cir, Carpinteria Dr, Barmouth Dr, Hillcrest Ave, Highway 4, and Highway 160. The western border is partitioned by Old River, Italian Slough, Western Farms Ranch Rd, Rankin Rd, Highway J14, Byron Hot Springs Rd, Camino Diablo, Kellogg Creek, Sellers Ave, Brentwood Blvd, Alloro Dr, Ghiggeri Dr, Emilio Dr, Guthrie Ln, Balfour Rd, Chestnut St, Byron Highway, Orwood Rd, Burlington Northern Santa Fe, Werner Dredger Cut, and Rock Slough.
Alameda County is split between this district and the 12th, 14th, and 17th districts. They are partitioned by Sinclair Freeway, Amador Valley Blvd, Emerald Ave, Tamarack Dr, Brighton Dr, Ione Way, Newcastle Ln, Dougherty Rd, Highway 580, Lembert Hills Dr.
Cities and CDPs with 10,000 or more people
- Concord – 125,410
- Antioch – 115,291
- San Ramon – 84,605
- Dublin – 72,589
- Walnut Creek – 70,127
- Brentwood – 64,292
- Danville – 43,582
- Oakley – 43,357
- Martinez – 37,287
- Pleasant Hill – 34,613
- Lafayette – 25,391
- Orinda – 19,514
- Moraga – 16,870
- Alamo – 15,314
- Clayton – 11,070
2,500 – 10,000 people
- Blackhawk – 9,647
- Contra Costa Centre – 6,808
- Saranap – 5,202
- Camino Tassajara – 4,951
- Pacheco – 4,183
- Vine Hill – 3,761
- San Miguel – 3,172
- Reliez Valley – 3,101
List of members representing the district