# California's 4th congressional district

California's 4th congressional district is a U.S. congressional district in California. The district is located in the northwestern part of the state, and includes all of Lake County and Napa County, most of Yolo County, and parts of Solano County and Sonoma County. Major cities in the district include Davis, Woodland, Napa, Vacaville, and most of Santa Rosa. The new 4th district is solidly Democratic, and is represented by Mike Thompson.
From 2013 to 2023, the district encompassed the Sierras from Truckee to the Sequoia National Forest, as well as a largely suburban area on the edge of the Sacramento Valley in southwestern Placer County. It consisted of Alpine, Amador, Calaveras, El Dorado, Mariposa, and Tuolumne counties plus most of Placer County and portions of Fresno, Madera, and Nevada counties. The district was represented by Republican Tom McClintock.

## Competitiveness

In 2006, Republicans had 48 percent of voter registrations, Democrats had 30 percent, and Libertarians had roughly 5 percent. A Democratic congressional candidate nearly won the district in 2008, losing by only half a percentage point and less than 1,600 votes, indicating that the district was much more competitive than it appeared to be.
New district boundaries for the 2012 elections shifted the population center to the south and east. Registered Democrats and Independents/Decline to State voters in the new district area outnumber registered Republicans by 12%. However, Republicans, Independents/Decline to State, and small third parties outnumber Democrats well over a 2 to 1 ratio. There were 183,800 Republicans, 117,300 Democrats, and 97,200 others. In presidential elections, Donald Trump won the district in 2016 with 54% of the vote and won in 2020 with 53.7% of the vote. In the 2018 and 2020 elections, the Republican candidate won over 53% of the vote.
In the 2020 redistricting, the district was shifted again to the San Francisco Bay Area. It includes all of Lake County and Napa County, most of Yolo County, and parts of Solano County and Sonoma County. Major cities in the district include Davis, Woodland, Napa, Vacaville, and most of Santa Rosa. The new 4th district is solidly Democratic, and is represented by Mike Thompson.

## Recent election results from statewide races

| Year | Office | Results |
| 2008 | President | Obama 67% - 32% |
| 2010 | Governor | Brown 59% - 36% |
| 2010 | Lt. Governor | Newsom 57% - 34% |
| 2010 | Secretary of State | Bowen 58% - 33% |
| 2010 | Attorney General | Harris 51% - 39% |
| 2010 | Treasurer | Lockyer 61% - 31% |
| 2010 | Controller | Chiang 61% - 29% |
| 2012 | President | Obama 66% - 34% |
| 2014 | Governor | Brown 68% - 32% |
| 2016 | President | Clinton 64% - 29% |
| 2018 | Governor | Newsom 65% - 35% |
| 2018 | Attorney General | Becerra 66% - 34% |
| 2020 | President | Biden 67% - 30% |
| 2022 | Senate (Reg.) | Padilla 66% - 34% |
| 2022 | Governor | Newsom 63% - 37% |
| 2022 | Lt. Governor | Kounalakis 65% - 35% |
| 2022 | Secretary of State | Weber 65% - 35% |
| 2022 | Attorney General | Bonta 64% - 36% |
| 2022 | Treasurer | Ma 64% - 36% |
| 2022 | Controller | Cohen 61% - 39% |
| 2024 | President | Harris 64% - 33% |
| 2024 | Senate (Reg.) | Schiff 64% - 36% |

## Composition

| FIPS County Code | County | Seat | Population |
| 33 | Lake | Lakeport | 68,878 |
| 55 | Napa | Napa | 133,216 |
| 95 | Solano | Fairfield | 449,218 |
| 97 | Sonoma | Santa Rosa | 481,812 |
| 113 | Yolo | Woodland | 220,544 |
Under the 2020 redistricting, California's 4th congressional district encompasses Lake, Napa, and Yolo Counties, and parts of Sonoma and Solano Counties. The area in Sonoma County includes the cities of Santa Rosa, Rohnert Park, Sonoma, Petaluma, and Cotati; and the census-designated places Boyes Hot Spring, El Verano, Penngrove, Sonoma State University, Kenwood, Glen Ellen, Eldridge, Fetters Hot Springs-Agua Caliente, and Temelec. The area in Solano County includes the cities of Vacaville, Dixon, and Rio Vista; and the census-designated places Hartley and Allendale.
Sonoma County is split between this district and the 2nd district. They are partitioned by Petaluma River, Highway 116, Redwood Highway, Robber Rd, Petersen Rd, Llano Rd, S Wright Rd, W College Ave, Jennings Ave, Administration Dr, Bicentennial Way, Cleveland Ave, Old Redwood Highway, Cross Creek Rd, Sonoma Highway, and Sonoma Creek.
Solano County is split between this district and the 8th district. They are partitioned by Soda Springs Rd, Union Pacific, Alamo Dr, Leisure Town Rd, Hawkins Rd, Bay Area Exxextric, Shilo Rd, Collinsville Rd, and Montezuma Slough.

### Cities and CDPs with 10,000 or more people

* Santa Rosa – 178,127
* Vacaville – 102,386
* Napa – 77,480
* Davis – 66,850
* Woodland – 61,032
* Petaluma – 59,776
* West Sacramento – 53,519
* Rohnert Park – 44,390
* American Canyon – 21,837
* Dixon – 18,988
* Clearlake – 16,685
* Sonoma – 11,024
* Rio Vista – 10,217

### 2,500 – 10,000 people

* University of California, Davis – 8,525
* Cotati – 7,584
* Winters – 7,195
* Hidden Valley Lake – 6,235
* Boyes Hot Springs – 6,215
* St. Helena – 5,438
* Calistoga – 5,228
* Lakeport – 5,026
* Penngrove – 4,172
* Fetters Hot Springs-Agua Caliente – 4,144
* El Verano – 3,867
* Yountville – 3,436
* Kelseyville – 3,382
* Clearlake Riviera (Kelseyville Riviera) – 3,410
* North Lakeport – 3,314
* Esparto – 3,108
* Lucerne – 3,067
* Esparto – 2,877
* Nice – 2,731
* Sonoma State University – 2,679
* Angwin – 2,633
* Clearlake Oaks – 2,551
* Hartley – 2,510

## List of members representing the district

| Member | Party | Dates | Cong ress | Electoral history | Counties |
| District created March 4, 1873 ||||||
| Sherman Otis Houghton (San Jose) | Republican | March 4, 1873 – March 3, 1875 | 43rd | Redistricted from the 1st district and re-elected in 1872. lost re-election. | Fresno, Inyo, Kern, Los Angeles, Mariposa, Merced, Mono, Monterey, San Bernardino, San Diego, San Luis Obispo, San Mateo, Santa Barbara, Santa Clara, Santa Cruz, Stanislaus, Tulare, Ventura |
| Peter D. Wigginton (Merced) | Democratic | March 4, 1875 – March 3, 1877 | 44th | Elected in 1875. Retired. | Fresno, Inyo, Kern, Los Angeles, Mariposa, Merced, Mono, Monterey, San Bernardino, San Diego, San Luis Obispo, San Mateo, Santa Barbara, Santa Clara, Santa Cruz, Stanislaus, Tulare, Ventura |
| Romualdo Pacheco (San Luis Obispo) | Republican | March 4, 1877 – February 7, 1878 | 45th | Lost contested election. | Fresno, Inyo, Kern, Los Angeles, Mariposa, Merced, Mono, Monterey, San Bernardino, San Diego, San Luis Obispo, San Mateo, Santa Barbara, Santa Clara, Santa Cruz, Stanislaus, Tulare, Ventura |
| Peter D. Wigginton (Merced) | Democratic | February 7, 1878 – March 3, 1879 | 45th | Won contested election. Retired. | Fresno, Inyo, Kern, Los Angeles, Mariposa, Merced, Mono, Monterey, San Bernardino, San Diego, San Luis Obispo, San Mateo, Santa Barbara, Santa Clara, Santa Cruz, Stanislaus, Tulare, Ventura |
| Romualdo Pacheco (San Luis Obispo) | Republican | March 4, 1879 – March 3, 1883 | 46th 47th | Elected in 1879. Re-elected in 1880. Retired. | Fresno, Inyo, Kern, Los Angeles, Mariposa, Merced, Mono, Monterey, San Bernardino, San Diego, San Luis Obispo, San Mateo, Santa Barbara, Santa Clara, Santa Cruz, Stanislaus, Tulare, Ventura |
| Pleasant B. Tully (Gilroy) | Democratic | March 4, 1883 – March 3, 1885 | 48th | Elected in 1882. Retired. | San Francisco |
| William W. Morrow (San Francisco) | Republican | March 4, 1885 – March 3, 1891 | 49th 50th 51st | Elected in 1884. Re-elected in 1886. Re-elected in 1888. Retired. | San Francisco |
| John T. Cutting (San Francisco) | Republican | March 4, 1891 – March 3, 1893 | 52nd | Elected in 1890. Retired. | San Francisco |
| James G. Maguire (San Francisco) | Democratic | March 4, 1893 – March 3, 1899 | 53rd 54th 55th | Elected in 1892. Re-elected in 1894. Re-elected in 1896. Lost re-election. | San Francisco |
| Julius Kahn (San Francisco) | Republican | March 4, 1899 – March 3, 1903 | 56th 57th | Elected in 1898. Re-elected in 1900. Lost re-election. | San Francisco |
| Edward J. Livernash (San Francisco) | Democratic/ Union Labor | March 4, 1903 – March 3, 1905 | 58th | Elected in 1902. Lost re-election. | San Francisco |
| Julius Kahn (San Francisco) | Republican | March 4, 1905 – December 18, 1924 | 59th 60th 61st 62nd 63rd 64th 65th 66th 67th 68th | Elected in 1904. Re-elected in 1906. Re-elected in 1908. Re-elected in 1910. Re-elected in 1912. Re-elected in 1914. Re-elected in 1916. Re-elected in 1918. Re-elected in 1920. Re-elected in 1922. Re-elected in 1924. Died. | San Francisco |
| Vacant | Vacant | December 18, 1924 – February 17, 1925 | 68th | | San Francisco |
| Florence Prag Kahn (San Francisco) | Republican | February 17, 1925 – January 3, 1937 | 68th 69th 70th 71st 72nd 73rd 74th | Elected to finish husband's term. Re-elected in 1926. Re-elected in 1928. Re-elected in 1930. Re-elected in 1932. Re-elected in 1934. Lost re-election. | San Francisco |
| Franck R. Havenner (San Francisco) | Progressive | January 3, 1937 – January 3, 1939 | 75th 76th | Elected in 1936. Re-elected in 1938. Lost re-election. | San Francisco |
| Franck R. Havenner (San Francisco) | Democratic | January 3, 1939 – January 3, 1941 | 75th 76th | Elected in 1936. Re-elected in 1938. Lost re-election. | San Francisco |
| Thomas Rolph (San Francisco) | Republican | January 3, 1941 – January 3, 1945 | 77th 78th | Elected in 1940. Re-elected in 1942. Lost re-election. | San Francisco |
| Franck R. Havenner (San Francisco) | Democratic | January 3, 1945 – January 3, 1953 | 79th 80th 81st 82nd | Elected in 1944. Re-elected in 1946. Re-elected in 1948. Re-elected in 1950. Lost re-election. | San Francisco |
| William S. Mailliard (San Francisco) | Republican | January 3, 1953 – January 3, 1963 | 83rd 84th 85th 86th 87th | Elected in 1952. Re-elected in 1954. Re-elected in 1956. Re-elected in 1958. Re-elected in 1960. Redistricted to the 6th district. | San Francisco |
| Robert Leggett (Vallejo) | Democratic | January 3, 1963 – January 3, 1979 | 88th 89th 90th 91st 92nd 93rd 94th 95th | Elected in 1962. Re-elected in 1964. Re-elected in 1966. Re-elected in 1968. Re-elected in 1970. Re-elected in 1972. Re-elected in 1974. Re-elected in 1976. Retired. | 1963–1967 Colusa, Glenn, Lake, Solano, Sutter, Yolo, Yuba |
| Robert Leggett (Vallejo) | Democratic | January 3, 1963 – January 3, 1979 | 88th 89th 90th 91st 92nd 93rd 94th 95th | Elected in 1962. Re-elected in 1964. Re-elected in 1966. Re-elected in 1968. Re-elected in 1970. Re-elected in 1972. Re-elected in 1974. Re-elected in 1976. Retired. | 1967–1973 Colusa, Glenn, Lake, Sacramento (outside the city), Solano, Sutter, Yolo, Yuba |
| Robert Leggett (Vallejo) | Democratic | January 3, 1963 – January 3, 1979 | 88th 89th 90th 91st 92nd 93rd 94th 95th | Elected in 1962. Re-elected in 1964. Re-elected in 1966. Re-elected in 1968. Re-elected in 1970. Re-elected in 1972. Re-elected in 1974. Re-elected in 1976. Retired. | 1973–1975 Colusa, Glenn, Solano, southwestern Sacramento, Sutter, Yolo, Yuba |
| Robert Leggett (Vallejo) | Democratic | January 3, 1963 – January 3, 1979 | 88th 89th 90th 91st 92nd 93rd 94th 95th | Elected in 1962. Re-elected in 1964. Re-elected in 1966. Re-elected in 1968. Re-elected in 1970. Re-elected in 1972. Re-elected in 1974. Re-elected in 1976. Retired. | 1975–1983 Colusa, western Sacramento, Solano, Sutter, Yolo |
| Vic Fazio (West Sacramento) | Democratic | January 3, 1979 – January 3, 1993 | 96th 97th 98th 99th 100th 101st 102nd | Elected in 1978. Re-elected in 1980. Re-elected in 1982. Re-elected in 1984. Re-elected in 1986. Re-elected in 1988. Re-elected in 1990. Redistricted to the 3rd district. | 1975–1983 Colusa, western Sacramento, Solano, Sutter, Yolo |
| Vic Fazio (West Sacramento) | Democratic | January 3, 1979 – January 3, 1993 | 96th 97th 98th 99th 100th 101st 102nd | Elected in 1978. Re-elected in 1980. Re-elected in 1982. Re-elected in 1984. Re-elected in 1986. Re-elected in 1988. Re-elected in 1990. Redistricted to the 3rd district. | 1983–1993 Sacramento (outside the city), Solano, Yolo |
| John Doolittle (Roseville) | Republican | January 3, 1993 – January 3, 2009 | 103rd 104th 105th 106th 107th 108th 109th 110th | Redistricted from the 14th district and re-elected in 1992. Re-elected in 1994. Re-elected in 1996. Re-elected in 1998. Re-elected in 2000. Re-elected in 2002. Re-elected in 2004. Re-elected in 2006. Retired. | 1993–2003 Alpine, Amador, Calaveras, El Dorado, Mono, Placer, northeastern Sacramento, Tuolumne |
| John Doolittle (Roseville) | Republican | January 3, 1993 – January 3, 2009 | 103rd 104th 105th 106th 107th 108th 109th 110th | Redistricted from the 14th district and re-elected in 1992. Re-elected in 1994. Re-elected in 1996. Re-elected in 1998. Re-elected in 2000. Re-elected in 2002. Re-elected in 2004. Re-elected in 2006. Retired. | 2003–2013 Eastern Butte, El Dorado, Lassen, Modoc, Nevada, Placer, Plumas, Sacramento (Orangevale), Sierra |
| Tom McClintock (Elk Grove) | Republican | January 3, 2009 – January 3, 2023 | 111th 112th 113th 114th 115th 116th 117th | Elected in 2008. Re-elected in 2010. Re-elected in 2012. Re-elected in 2014. Re-elected in 2016. Re-elected in 2018. Re-elected in 2020. Redistricted to the 3rd district. | 2003–2013 Eastern Butte, El Dorado, Lassen, Modoc, Nevada, Placer, Plumas, Sacramento (Orangevale), Sierra |
| Tom McClintock (Elk Grove) | Republican | January 3, 2009 – January 3, 2023 | 111th 112th 113th 114th 115th 116th 117th | Elected in 2008. Re-elected in 2010. Re-elected in 2012. Re-elected in 2014. Re-elected in 2016. Re-elected in 2018. Re-elected in 2020. Redistricted to the 3rd district. | 2013–2023 Eastern central California including Lake Tahoe, Roseville, and Yosemite National Park |
| Mike Thompson (St. Helena) | Democratic | January 3, 2023 – present | 118th 119th | Redistricted from the 5th district and re-elected in 2022. Re-elected in 2024. | 2023–present Lake, Napa, most of Yolo, parts of Solano and Sonoma |

## Election results for representatives
### 1872

1872 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Republican | Sherman Otis Houghton (Incumbent) | 10,391 | 53.5 |
| | Democratic | Edward J. Kewen | 9,012 | 46.5 |
| Total votes | Total votes | Total votes | 19,403 | 100.0 |
| Turnout | Turnout | Turnout | | |
| | Republican hold | Republican hold | Republican hold | Republican hold |

### 1874

1874 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Democratic | Peter D. Wigginton | 15,649 | 48.8 |
| | Republican | Sherman Otis Houghton (Incumbent) | 11,090 | 34.6 |
| | Independent | J. S. Thompson | 5,343 | 16.7 |
| Total votes | Total votes | Total votes | 32,082 | 100.0 |
| Turnout | Turnout | Turnout | | |
| | Democratic gain from Republican | Democratic gain from Republican | Democratic gain from Republican | Democratic gain from Republican |

### 1876

1876 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Republican | Romualdo Pacheco | 19,104 | 50.0 |
| | Democratic | Peter D. Wigginton (Incumbent) | 19,103 | 50.0 |
| Total votes | Total votes | Total votes | 38,207 | 100.0 |
| Turnout | Turnout | Turnout | | |
| | Republican gain from Democratic | Republican gain from Democratic | Republican gain from Democratic | Republican gain from Democratic |

### 1878

1878 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Republican | Romualdo Pacheco | 15,391 | 40.5 |
| | Democratic | Wallace A. Leach | 12,109 | 31.8 |
| | Workingman's | James J. Ayers | 10,527 | 27.7 |
| Total votes | Total votes | Total votes | 38,027 | 100.0 |
| Turnout | Turnout | Turnout | | |
| | Republican hold | Republican hold | Republican hold | Republican hold |

### 1880

1880 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Republican | Romualdo Pacheco (Incumbent) | 17,768 | 45.8 |
| | Democratic | Wallace A. Leach | 17,577 | 45.3 |
| | Greenback | J. F. Godfrey | 3,435 | 8.9 |
| Total votes | Total votes | Total votes | 38,780 | 100.0 |
| Turnout | Turnout | Turnout | | |
| | Republican hold | Republican hold | Republican hold | Republican hold |

### 1882

1882 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Democratic | Pleasant B. Tully | 23,105 | 54.4 |
| | Republican | George Lemuel Woods | 18,387 | 43.3 |
| | Populist | M. V. Wright | 650 | 1.5 |
| | Prohibition | Isaac Kinley | 355 | 0.8 |
| Total votes | Total votes | Total votes | 42,497 | 100.0 |
| Turnout | Turnout | Turnout | | |
| | Democratic gain from Republican | Democratic gain from Republican | Democratic gain from Republican | Democratic gain from Republican |

### 1884

1884 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Republican | William W. Morrow | 15,083 | 58.8 |
| | Democratic | R. P. Hastings | 10,422 | 40.6 |
| | Populist | H. S. Fitch | 123 | 0.5 |
| | Prohibition | George Babcock | 15 | 0.1 |
| Total votes | Total votes | Total votes | 25,643 | 100.0 |
| Turnout | Turnout | Turnout | | |
| | Republican gain from Democratic | Republican gain from Democratic | Republican gain from Democratic | Republican gain from Democratic |

### 1886

1886 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Republican | William W. Morrow (Incumbent) | 11,413 | 48.6 |
| | Democratic | Frank McCoppin | 9,854 | 42.0 |
| | Independent | Charles Allen Sumner | 2,104 | 9.0 |
| | Prohibition | Robert Thompson | 84 | 0.4 |
| Total votes | Total votes | Total votes | 23,455 | 100.0 |
| Turnout | Turnout | Turnout | | |
| | Republican hold | Republican hold | Republican hold | Republican hold |

### 1888

1888 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Republican | William W. Morrow (Incumbent) | 14,217 | 50.8 |
| | Democratic | Robert Ferral | 13,624 | 48.6 |
| | Socialist | Frank M. Pixley | 173 | 0.6 |
| Total votes | Total votes | Total votes | 28,014 | 100.0 |
| Turnout | Turnout | Turnout | | |
| | Republican hold | Republican hold | Republican hold | Republican hold |

### 1890

1890 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Republican | John Tyler Cutting | 13,196 | 49.2 |
| | Democratic | Robert Ferral | 12,091 | 45.1 |
| | Socialist | Thomas V. Cator | 1,492 | 5.6 |
| | Prohibition | Joseph Rowell | 50 | 0.2 |
| Total votes | Total votes | Total votes | 26,829 | 100.0 |
| Turnout | Turnout | Turnout | | |
| | Republican hold | Republican hold | Republican hold | Republican hold |

### 1892

1892 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Democratic | James G. Maguire | 14,997 | 49.2 |
| | Republican | Charles O. Alexander | 13,226 | 43.4 |
| | Populist | Edgar P. Burman | 1,980 | 6.5 |
| | Prohibition | Henry Collins | 296 | 1.0 |
| Total votes | Total votes | Total votes | 30,499 | 100.0 |
| Turnout | Turnout | Turnout | | |
| | Democratic gain from Republican | Democratic gain from Republican | Democratic gain from Republican | Democratic gain from Republican |

### 1894

1894 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Democratic | James G. Maguire (Incumbent) | 14,748 | 48.3 |
| | Republican | Thomas B. Shannon | 9,785 | 32.0 |
| | Populist | B. K. Collier | 5,627 | 18.4 |
| | Prohibition | Joseph Rowell | 388 | 1.3 |
| Total votes | Total votes | Total votes | 30,548 | 100.0 |
| Turnout | Turnout | Turnout | | |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

### 1896

1896 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Democratic | James G. Maguire (Incumbent) | 19,074 | 61.0 |
| | Republican | Thomas B. O'Brien | 10,940 | 35.0 |
| | Socialist Labor | E. T. Kingsley | 968 | 3.0 |
| | Prohibition | Joseph Rowell | 299 | 1.0 |
| Total votes | Total votes | Total votes | 31,281 | 100.0 |
| Turnout | Turnout | Turnout | | |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

### 1898

1898 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Republican | Julius Kahn | 13,695 | 50.0 |
| | Democratic | James H. Barry | 12,084 | 44.1 |
| | Socialist Labor | W. J. Martin | 1,006 | 3.7 |
| | Independent | Joseph P. Kelly | 594 | 2.2 |
| Total votes | Total votes | Total votes | 27,379 | 100.0 |
| Turnout | Turnout | Turnout | | |
| | Republican gain from Democratic | Republican gain from Democratic | Republican gain from Democratic | Republican gain from Democratic |

### 1900

1900 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Republican | Julius Kahn (Incumbent) | 17,111 | 55.2 |
| | Democratic | R. Porter Ashe | 11,742 | 37.8 |
| | Independent | C. C. O'Donnell | 1,116 | 3.6 |
| | Socialist | G. B. Benham | 969 | 3.1 |
| | Prohibition | Joseph Rowell | 84 | 0.3 |
| Total votes | Total votes | Total votes | 31,022 | 100.0 |
| Turnout | Turnout | Turnout | | |
| | Republican hold | Republican hold | Republican hold | Republican hold |

### 1902

1902 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Democratic | Edward J. Livernash | 16,146 | 49.2 |
| | Republican | Julius Kahn (Incumbent) | 16,005 | 48.7 |
| | Socialist | William Costley | 616 | 1.9 |
| | Prohibition | Joseph Rowell | 69 | 0.2 |
| Total votes | Total votes | Total votes | 16,836 | 100.0 |
| Turnout | Turnout | Turnout | | |
| | Democratic gain from Republican | Democratic gain from Republican | Democratic gain from Republican | Democratic gain from Republican |

### 1904

1904 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Republican | Julius Kahn | 20,012 | 57.0 |
| | Democratic | Edward J. Livernash (Incumbent) | 12,812 | 36.4 |
| | Socialist | William Costley | 2,267 | 6.4 |
| Total votes | Total votes | Total votes | 35,091 | 100.0 |
| Turnout | Turnout | Turnout | | |
| | Republican gain from Democratic | Republican gain from Democratic | Republican gain from Democratic | Republican gain from Democratic |

### 1906

1906 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Republican | Julius Kahn (Incumbent) | 5,678 | 62.4 |
| | Democratic | David S. Hirshberg | 3,016 | 33.2 |
| | Socialist | Oliver Everett | 399 | 4.4 |
| Total votes | Total votes | Total votes | 9,093 | 100.0 |
| Turnout | Turnout | Turnout | | |
| | Republican hold | Republican hold | Republican hold | Republican hold |

### 1908

1908 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Republican | Julius Kahn (Incumbent) | 9,202 | 52.7 |
| | Democratic | James G. Maguire | 7,497 | 42.9 |
| | Socialist | K. J. Doyle | 699 | 4.0 |
| | Prohibition | William N. Meserve | 60 | 0.3 |
| Total votes | Total votes | Total votes | 17,458 | 100.0 |
| Turnout | Turnout | Turnout | | |
| | Republican hold | Republican hold | Republican hold | Republican hold |

### 1910

1910 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Republican | Julius Kahn (Incumbent) | 10,188 | 56.5 |
| | Democratic | Walter MacArthur | 6,636 | 36.8 |
| | Socialist | Austin Lewis | 1,178 | 6.5 |
| | Prohibition | E. F. Dinsmore | 35 | 0.2 |
| Total votes | Total votes | Total votes | 18,037 | 100.0 |
| Turnout | Turnout | Turnout | | |
| | Republican hold | Republican hold | Republican hold | Republican hold |

### 1912

1912 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Republican | Julius Kahn (Incumbent) | 25,515 | 56.1 |
| | Democratic | Bert Schlesinger | 14,884 | 32.7 |
| | Socialist | Norman W. Pendleton | 5,090 | 11.2 |
| Total votes | Total votes | Total votes | 45,489 | 100.0 |
| Turnout | Turnout | Turnout | | |
| | Republican hold | Republican hold | Republican hold | Republican hold |

### 1914

1914 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Republican | Julius Kahn (Incumbent) | 41,044 | 69.1 |
| | Democratic | Henry Colombat | 13,550 | 22.8 |
| | Socialist | Allen K. Gifford | 3,928 | 6.6 |
| | Prohibition | J. C. Westenberg | 895 | 1.5 |
| Total votes | Total votes | Total votes | 59,417 | 100.0 |
| Turnout | Turnout | Turnout | | |
| | Republican hold | Republican hold | Republican hold | Republican hold |

### 1916

1916 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Republican | Julius Kahn (Incumbent) | 51,968 | 77.2 |
| | Democratic | J. M. Fernald | 10,579 | 15.7 |
| | Socialist | Allen K. Gifford | 3,775 | 5.6 |
| | Prohibition | Henry W. Hutchinson | 981 | 1.5 |
| Total votes | Total votes | Total votes | 67,303 | 100.0 |
| Turnout | Turnout | Turnout | | |
| | Republican hold | Republican hold | Republican hold | Republican hold |

### 1918

1918 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Republican | Julius Kahn (Incumbent) | 38,278 | 86.6 |
| | Socialist | Hugo Ernst | 5,913 | 13.4 |
| Total votes | Total votes | Total votes | 43,191 | 100.0 |
| Turnout | Turnout | Turnout | | |
| | Republican hold | Republican hold | Republican hold | Republican hold |

### 1920

1920 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Republican | Julius Kahn (Incumbent) | 50,841 | 84.6 |
| | Socialist | Hugo Ernst | 9,289 | 15.4 |
| Total votes | Total votes | Total votes | 60,130 | 100.0 |
| Turnout | Turnout | Turnout | | |
| | Republican hold | Republican hold | Republican hold | Republican hold |

### 1922

1922 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Republican | Julius Kahn (Incumbent) | 46,527 | 83 |
| | Socialist | Hugo Ernst | 9,547 | 17 |
| Total votes | Total votes | Total votes | 56,074 | 100 |
| Turnout | Turnout | Turnout | | |
| | Republican hold | Republican hold | Republican hold | Republican hold |

### 1924

1924 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Republican | Julius Kahn (Incumbent) | 44,048 | 81 |
| | Socialist | William McDevitt | 10,360 | 19 |
| Total votes | Total votes | Total votes | 54,408 | 100 |
| Turnout | Turnout | Turnout | | |
| | Republican hold | Republican hold | Republican hold | Republican hold |

### 1926

1926 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Republican | Florence Prag Kahn (Incumbent) | 37,353 | 63.4 |
| | Democratic | Chauncey F. Tramutulo | 18,210 | 32.5 |
| | Socialist | Harry W. Hutton | 2,960 | 5.1 |
| Total votes | Total votes | Total votes | 58,523 | 100.0 |
| Turnout | Turnout | Turnout | | |
| | Republican hold | Republican hold | Republican hold | Republican hold |

### 1928

1928 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Republican | Florence Prag Kahn (Incumbent) | 50,206 | 76 |
| | Independent | Harry W. Hutton | 16,838 | 24 |
| Total votes | Total votes | Total votes | 67,044 | 100 |
| Turnout | Turnout | Turnout | | |
| | Republican hold | Republican hold | Republican hold | Republican hold |

### 1930

1930 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Republican | Florence Prag Kahn (Incumbent) | 47,397 | 100.0 |
| Turnout | Turnout | Turnout | | |
| | Republican hold | Republican hold | Republican hold | Republican hold |

### 1932

1932 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Republican | Florence Prag Kahn (Incumbent) | 67,425 | 85.3 |
| | Socialist | Milen C. Dempster | 11,603 | 14.7 |
| Total votes | Total votes | Total votes | 79,028 | 100.0 |
| Turnout | Turnout | Turnout | | |
| | Republican hold | Republican hold | Republican hold | Republican hold |

### 1934

1934 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Republican | Florence Prag Kahn (Incumbent) | 50,491 | 48.0 |
| | Democratic | Chauncey Tramutolo | 46,871 | 44.5 |
| | Progressive | Raymond A. Burr | 3,636 | 3.5 |
| | Socialist | Samuel S. White | 2,414 | 2.3 |
| | Communist | Minnie Carson | 1,810 | 1.7 |
| Total votes | Total votes | Total votes | 105,222 | 100.0 |
| Turnout | Turnout | Turnout | | |
| | Republican hold | Republican hold | Republican hold | Republican hold |

### 1936

1936 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Progressive | Franck R. Havenner | 64,063 | 58.5 |
| | Republican | Florence Prag Kahn (Incumbent) | 43,805 | 40.0 |
| | Communist | Anita Whitney | 1,711 | 1.5 |
| Total votes | Total votes | Total votes | 109,579 | 100.0 |
| Turnout | Turnout | Turnout | | |
| | Progressive gain from Republican | Progressive gain from Republican | Progressive gain from Republican | Progressive gain from Republican |

### 1938

1938 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Democratic | Franck R. Havenner (Incumbent) | 64,452 | 61.2 |
| | Republican | Kennett B. Dawson | 40,842 | 38.8 |
| Total votes | Total votes | Total votes | 105,294 | 100.0 |
| Turnout | Turnout | Turnout | | |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

### 1940

1940 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Republican | Thomas Rolph | 75,369 | 54.6 |
| | Democratic | Franck R. Havenner (Incumbent) | 61,341 | 44.4 |
| | Communist | Archie Brown | 1,322 | 1.0 |
| Total votes | Total votes | Total votes | 138,032 | 100.0 |
| Turnout | Turnout | Turnout | | |
| | Republican gain from Democratic | Republican gain from Democratic | Republican gain from Democratic | Republican gain from Democratic |

### 1942

1942 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Republican | Thomas Rolph (Incumbent) | 62,735 | 98.3 |
| | Communist | Archie Brown (write-in) | 1,116 | 1.7 |
| Total votes | Total votes | Total votes | 63,851 | 100.0 |
| Turnout | Turnout | Turnout | | |
| | Republican hold | Republican hold | Republican hold | Republican hold |

### 1944

1944 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Democratic | Franck R. Havenner | 73,582 | 50.1 |
| | Republican | Thomas Rolph (Incumbent) | 73,367 | 49.9 |
| Total votes | Total votes | Total votes | 146,949 | 100.0 |
| Turnout | Turnout | Turnout | | |
| | Democratic gain from Republican | Democratic gain from Republican | Democratic gain from Republican | Democratic gain from Republican |

### 1946

1946 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Democratic | Franck R. Havenner (Incumbent) | 60,655 | 52.9 |
| | Republican | Truman R. Young | 54,113 | 47.1 |
| Total votes | Total votes | Total votes | 114,768 | 100.0 |
| Turnout | Turnout | Turnout | | |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

### 1948

1948 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Democratic | Franck R. Havenner (Incumbent) | 73,704 | 51.0 |
| | Republican | William S. Mailliard | 68,875 | 47.7 |
| | Progressive | Francis J. McTernan Jr. | 1,949 | 1.3 |
| Total votes | Total votes | Total votes | 144,528 | 100.0 |
| Turnout | Turnout | Turnout | | |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

### 1950

1950 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Democratic | Franck R. Havenner (Incumbent) | 83,078 | 67.2 |
| | Republican | Raymond D. Smith | 40,569 | 32.8 |
| Total votes | Total votes | Total votes | 123,647 | 100.0 |
| Turnout | Turnout | Turnout | | |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

### 1952

1952 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Republican | William S. Mailliard | 102,359 | 55 |
| | Democratic | Franck R. Havenner (Incumbent) | 83,748 | 45 |
| Total votes | Total votes | Total votes | 186,107 | 100 |
| Turnout | Turnout | Turnout | | |
| | Republican gain from Democratic | Republican gain from Democratic | Republican gain from Democratic | Republican gain from Democratic |

### 1954

1954 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Republican | William S. Mailliard (Incumbent) | 88,439 | 61.2 |
| | Democratic | Philip A. O'Rourke | 52,980 | 36.7 |
| | Progressive | George R. Andersen | 2,987 | 2.1 |
| Total votes | Total votes | Total votes | 144,406 | 100.0 |
| Turnout | Turnout | Turnout | | |
| | Republican hold | Republican hold | Republican hold | Republican hold |

### 1956

1956 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Republican | William S. Mailliard (Incumbent) | 109,188 | 61.9 |
| | Democratic | James L. Quigley | 67,132 | 38.1 |
| Total votes | Total votes | Total votes | 176,320 | 100.0 |
| Turnout | Turnout | Turnout | | |
| | Republican hold | Republican hold | Republican hold | Republican hold |

### 1958

1958 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Republican | William S. Mailliard (Incumbent) | 98,574 | 63.9 |
| | Democratic | George D. Collins Jr. | 65,798 | 36.1 |
| Total votes | Total votes | Total votes | 164,372 | 100.0 |
| Turnout | Turnout | Turnout | | |
| | Republican hold | Republican hold | Republican hold | Republican hold |

### 1960

1960 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Republican | William S. Mailliard (Incumbent) | 118,249 | 65.3 |
| | Democratic | Phillips S. Davies | 62,814 | 34.7 |
| Total votes | Total votes | Total votes | 181,063 | 100.0 |
| Turnout | Turnout | Turnout | | |
| | Republican hold | Republican hold | Republican hold | Republican hold |

### 1962

1962 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Democratic | Robert L. Leggett | 55,563 | 56.5 |
| | Republican | L. V. Honsinger | 42,762 | 43.5 |
| Total votes | Total votes | Total votes | 98,325 | 100.0 |
| Turnout | Turnout | Turnout | | |
| | Democratic win (new seat) | Democratic win (new seat) | Democratic win (new seat) | Democratic win (new seat) |

### 1964

1964 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Democratic | Robert L. Leggett (Incumbent) | 84,949 | 71.9 |
| | Republican | Ivan Norris | 33,160 | 28.1 |
| Total votes | Total votes | Total votes | 118,109 | 100.0 |
| Turnout | Turnout | Turnout | | |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

### 1966

1966 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Democratic | Robert L. Leggett (Incumbent) | 67,942 | 60 |
| | Republican | Tom McHatton | 46,337 | 40 |
| Total votes | Total votes | Total votes | 114,279 | 100.0 |
| Turnout | Turnout | Turnout | | |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

### 1968

1968 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Democratic | Robert L. Leggett (Incumbent) | 88,067 | 55.5 |
| | Republican | James Shumway | 65,942 | 41.6 |
| | American Independent | Gene Clark | 4,545 | 2.9 |
| Total votes | Total votes | Total votes | 158,554 | 100.0 |
| Turnout | Turnout | Turnout | | |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

### 1970

1970 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Democratic | Robert L. Leggett (Incumbent) | 103,485 | 68 |
| | Republican | Andrew Gyorke | 48,783 | 32 |
| Total votes | Total votes | Total votes | 152,268 | 100 |
| Turnout | Turnout | Turnout | | |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

### 1972

1972 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Democratic | Robert L. Leggett (Incumbent) | 114,673 | 67.4 |
| | Republican | Benjamin Chang | 55,367 | 32.6 |
| Total votes | Total votes | Total votes | 170,040 | 100.0 |
| Turnout | Turnout | Turnout | | |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

### 1974

1974 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Democratic | Robert L. Leggett (Incumbent) | 100,934 | 100.0 |
| Turnout | Turnout | Turnout | | |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

### 1976

1976 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Democratic | Robert L. Leggett (Incumbent) | 75,844 | 50.2 |
| | Republican | Rex Hime | 75,193 | 49.8 |
| Total votes | Total votes | Total votes | 151,037 | 100.0 |
| Turnout | Turnout | Turnout | | |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

### 1978

1978 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Democratic | Vic Fazio | 87,764 | 55.4 |
| | Republican | Rex Hime | 70,733 | 44.6 |
| Total votes | Total votes | Total votes | 158,497 | 100.0 |
| Turnout | Turnout | Turnout | | |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

### 1980

1980 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Democratic | Vic Fazio (Incumbent) | 133,853 | 65.3 |
| | Republican | Albert Dehr | 60,935 | 29.7 |
| | Libertarian | Robert J. Burnside | 10,267 | 5.0 |
| Total votes | Total votes | Total votes | 205,055 | 100.0 |
| Turnout | Turnout | Turnout | | |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

### 1982

1982 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Democratic | Vic Fazio (Incumbent) | 118,476 | 63.9 |
| | Republican | Roger B. Canfield | 67,047 | 36.1 |
| Total votes | Total votes | Total votes | 185,523 | 100.0 |
| Turnout | Turnout | Turnout | | |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

### 1984

1984 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Democratic | Vic Fazio (Incumbent) | 130,109 | 61.4 |
| | Republican | Roger B. Canfield | 77,773 | 36.7 |
| | Libertarian | Roger Conant Pope | 4,039 | 1.9 |
| Total votes | Total votes | Total votes | 211,921 | 100.0 |
| Turnout | Turnout | Turnout | | |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

### 1986

1986 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Democratic | Vic Fazio (Incumbent) | 128,364 | 70.2 |
| | Republican | Jack D. Hite | 54,596 | 29.8 |
| Total votes | Total votes | Total votes | 182,960 | 100.0 |
| Turnout | Turnout | Turnout | | |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

### 1988

1988 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Democratic | Vic Fazio (Incumbent) | 181,184 | 100.0 |
| | No party | Write-ins | 1,306 | 0.0 |
| Turnout | Turnout | Turnout | | |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

### 1990

1990 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Democratic | Vic Fazio (Incumbent) | 115,090 | 54.7 |
| | Republican | Mark R. Baughman | 82,738 | 39.3 |
| | Libertarian | Bryce Bigwood | 12,626 | 6.0 |
| Total votes | Total votes | Total votes | 210,454 | 100.0 |
| Turnout | Turnout | Turnout | | |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

### 1992

1992 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Republican | John Doolittle (Incumbent) | 141,155 | 49.8 |
| | Democratic | Patricia Malberg | 129,489 | 45.7 |
| | Libertarian | Patrick Lee McHargue | 12,705 | 4.5 |
| | No party | Brooksher (write-in) | 16 | 0.0 |
| Total votes | Total votes | Total votes | 283,265 | 100.0 |
| Turnout | Turnout | Turnout | | |
| | Republican hold | Republican hold | Republican hold | Republican hold |

### 1994

1994 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Republican | John Doolittle (Incumbent) | 144,936 | 61.33 |
| | Democratic | Katie Hirning | 82,505 | 34.91 |
| | Libertarian | Damon C. Falconi | 8,882 | 3.76 |
| Total votes | Total votes | Total votes | 236,323 | 100.0 |
| Turnout | Turnout | Turnout | | |
| | Republican hold | Republican hold | Republican hold | Republican hold |

### 1996

1996 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Republican | John Doolittle (Incumbent) | 164,048 | 60.5 |
| | Democratic | Katie Hirning | 97,948 | 36.1 |
| | Libertarian | Patrick McHargue | 9,319 | 3.4 |
| Total votes | Total votes | Total votes | 271,315 | 100.0 |
| Turnout | Turnout | Turnout | | |
| | Republican hold | Republican hold | Republican hold | Republican hold |

### 1998

1998 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Republican | John Doolittle (Incumbent) | 155,306 | 62.57 |
| | Democratic | David Shapiro | 85,394 | 34.40 |
| | Libertarian | Dan Winterrowd | 7,524 | 3.03 |
| Total votes | Total votes | Total votes | 248,224 | 100.0 |
| Turnout | Turnout | Turnout | | |
| | Republican hold | Republican hold | Republican hold | Republican hold |

### 2000

2000 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Republican | John Doolittle (Incumbent) | 197,503 | 63.5 |
| | Democratic | Mark A. Norberg | 97,974 | 31.5 |
| | Libertarian | William Fritz Frey | 9,494 | 3.0 |
| | Natural Law | Robert E. Ray | 6,452 | 2.0 |
| Total votes | Total votes | Total votes | 311,423 | 100.0 |
| Turnout | Turnout | Turnout | | |
| | Republican hold | Republican hold | Republican hold | Republican hold |

### 2002

2002 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Republican | John Doolittle (Incumbent) | 139,280 | 64.9 |
| | Democratic | Mark A. Norberg | 68,755 | 32.0 |
| | Libertarian | Allen M. Roberts | 6,834 | 3.1 |
| Total votes | Total votes | Total votes | 214,869 | 100.0 |
| Turnout | Turnout | Turnout | | |
| | Republican hold | Republican hold | Republican hold | Republican hold |

### 2004

2004 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Republican | John Doolittle (Incumbent) | 221,926 | 65.4 |
| | Democratic | David I. Winters | 117,443 | 34.6 |
| Total votes | Total votes | Total votes | 339,369 | 100.0 |
| Turnout | Turnout | Turnout | | |
| | Republican hold | Republican hold | Republican hold | Republican hold |

### 2006

2006 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Republican | John Doolittle (Incumbent) | 135,818 | 49.1 |
| | Democratic | Charlie Brown | 126,999 | 45.9 |
| | Libertarian | Dan Warren | 14,076 | 5.0 |
| Total votes | Total votes | Total votes | 213,984 | 100.0 |
| Turnout | Turnout | Turnout | | |
| | Republican hold | Republican hold | Republican hold | Republican hold |

### 2008

2008 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Republican | Tom McClintock | 184,543 | 50.3 |
| | Democratic | Charlie Brown | 182,967 | 49.7 |
| Total votes | Total votes | Total votes | 367,510 | 100.0 |
| Turnout | Turnout | Turnout | | |
| | Republican hold | Republican hold | Republican hold | Republican hold |

### 2010

2010 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Republican | Tom McClintock | 186,392 | 61% |
| | Democratic | Clint Curtis | 95,653 | 31% |
| | Green | Benjamin Emery | 22,179 | 8% |
| Total votes | Total votes | Total votes | 304,224 | 100% |
| Turnout | Turnout | Turnout | | |
| | Republican hold | Republican hold | Republican hold | Republican hold |

### 2012

United States House of Representatives elections, 2012 :
| Party | Party | Candidate | Votes | % |
| | Republican | Tom McClintock (Incumbent) | 197,803 | 61.1% |
| | Democratic | Jack Uppal | 125,885 | 38.9% |
| Total votes | Total votes | Total votes | 323,688 | 100.0% |
| | Republican hold | Republican hold | Republican hold | Republican hold |

### 2014

United States House of Representatives elections, 2014 :
| Party | Party | Candidate | Votes | % |
| | Republican | Tom McClintock (Incumbent) | 126,784 | 60.0% |
| | Republican | Arthur "Art" Moore | 84,350 | 40.0% |
| Total votes | Total votes | Total votes | 211,134 | 100.0% |
| | Republican hold | Republican hold | Republican hold | Republican hold |

### 2016

United States House of Representatives elections, 2016 :
| Party | Party | Candidate | Votes | % |
| | Republican | Tom McClintock (Incumbent) | 220,133 | 62.7% |
| | Democratic | Robert W. Derlet | 130,845 | 37.3% |
| Total votes | Total votes | Total votes | 350,978 | 100.0% |
| | Republican hold | Republican hold | Republican hold | Republican hold |

### 2018

2018 United States House of Representatives elections :
| Party | Party | Candidate | Votes | % |
| | Republican | Tom McClintock | 184,401 | 54.1% |
| | Democratic | Jessica Morse | 156,253 | 45.9% |
| Total votes | Total votes | Total votes | 340,654 | 100% |
| Turnout | Turnout | Turnout | | |
| | Republican hold | Republican hold | Republican hold | Republican hold |
In 2018, six Democratic candidates filed statements of candidacy with the Federal Election Commission (FEC). They were, in alphabetical order by last name: Regina Bateson; Roza Calderon; Richard Martin; Robert Lawton; Jessica Morse; and Rochelle Wilcox. Martin and Wilcox dropped out of the race, with Wilcox endorsing Morse in February.
Retired Air Force Lieutenant Colonel Charlie Brown, who was the Democratic nominee for this seat in 2006 and 2008, was "seriously considering" running in 2018, but decided in June 2017 against a third campaign. In January 2018, Brown endorsed Morse for the nomination. Bob Derlet, the Democratic nominee in 2016, also endorsed Morse in January.
On the Republican side, McClintock had one challenger, Mitchell Kendrick White, who filed with the FEC in January.
In February, the California Democratic Party (CDP) endorsed Jessica Morse in a contested nomination. Roza Calderon was able to successfully collect 322 CDP-credentialed delegate signatures needed to block the endorsement, in which Morse only received 44 delegate votes. However, CDP staff refused to accept the forms after it was alleged they closed doors early to prevent the submission. A petition was later filed with the Compliance Review Commission (CRC) by Calderon. The CRC voted to accept and count the signatures, ultimately disqualifying enough signatures to proceed with Morse's endorsement.
California allows candidates to include their professional description under their names on the ballot. Regina Bateson challenged Morse's ballot designation title of "National Security Fellow" at the Sacramento Superior Court after months of controversy that Morse was "fluffing" her credentials. California's Secretary of State, Alex Padilla, struck down Morse's three ballot designations before Judge Gevercer ruled that she presented "no credible evidence" to use the ballot designation of "National Security Fellow". Instead, he held that this title would mislead the average person about her recent activities. In the official Certified Candidate List for the primary election, Morse's ballot designation was left blank.
Under the California nonpartisan blanket ("jungle") primary system, only the two candidates with the most votes on June 5, regardless of party, went on to the general election on November 6. Two Republicans and four Democrats appeared on the primary ballot. Morse finished second, qualifying for the general election ballot, along with McClintock.
For the November ballot, Morse was also denied "National Security" as her designation. In the November general election, McClintock held the district with an advantage of more than eight percentage points.

### 2020

2020 United States House of Representatives elections in California :
| Party | Party | Candidate | Votes | % |
| | Republican | Tom McClintock (incumbent) | 247,291 | 55.9 |
| | Democratic | Brynne S. Kennedy | 194,731 | 44.1 |
| Total votes | Total votes | Total votes | 442,022 | 100.0 |
| | Republican hold | Republican hold | Republican hold | Republican hold |

### 2022

2022 United States House of Representatives elections in California :
| Party | Party | Candidate | Votes | % |
| | Democratic | Mike Thompson (incumbent) | 176,900 | 67.8 |
| | Republican | Matt Brock | 84,007 | 32.2 |
| Total votes | Total votes | Total votes | 260,907 | 100.0 |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

### 2024

2024 United States House of Representatives elections in California :
| Party | Party | Candidate | Votes | % |
| | Democratic | Mike Thompson (incumbent) | 227,730 | 66.5 |
| | Republican | John Munn | 114,950 | 33.5 |
| Total votes | Total votes | Total votes | 342,680 | 100.0 |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold |