San Mateo County, California: Deep Blue Country
California · Presidential Elections 1876–2024
D+50.3
2024 Margin
R+7.4%
2020→2024 Swing
D since 1988
Voting Streak
764K
Population
San Mateo County, California voted D+50.3 for Kamala Harris in 2024, with Harris receiving 242,957 votes (73.5%). This represented a R+7.4% swing toward Republicans compared to 2020. The county has voted Democratic in every presidential election since 1988.
Quick Stats
2024 ResultD+50.3
2020→2024 SwingR+7.4%
Voting StreakD since 1988
Elections on Record38
Demographics
Population764,442
Median Age
40.3(US: 38.4)
College (BA+)
77.0%(US: 47.9%)
Median Income
$149,907(US: $78k)
White (non-Hisp)
35.8%(US: 57.5%)
Hispanic
24.9%(US: 18.6%)
Black
2.0%(US: 12.3%)
Asian
30.5%(US: 5.7%)
Homeownership
59.1%(US: 64.2%)
Poverty Rate
6.5%(US: 12.4%)
Veterans
3.1%(US: 6.4%)
Community Profile
Presidential Elections
Presidential Results
| Year | Democrat | Republican | Margin | Swing |
|---|---|---|---|---|
| 2024 | 73.5%(242,957) | 23.2%(76,616) | D+50.3 | R+7.4 |
| 2020 | 77.9%(291,496) | 20.2%(75,584) | D+57.7 | D+0.4 |
| 2016 | 75.7%(237,882) | 18.4%(57,929) | D+57.2 | D+10.6 |
| 2012 | 72.1%(206,085) | 25.5%(72,756) | D+46.7 | R+2.1 |
| 2008 | 73.5%(222,826) | 24.8%(75,057) | D+48.7 | D+8.5 |
| 2004 | 69.5%(197,922) | 29.3%(83,315) | D+40.2 | D+6.9 |
| 2000 | 64.3%(166,757) | 30.9%(80,296) | D+33.3 | D+2.0 |
| 1996 | 60.5%(152,304) | 29.2%(73,508) | D+31.3 | D+4.5 |
| 1992 | 54.0%(149,232) | 27.1%(75,080) | D+26.8 | D+14.0 |
| 1988 | 55.7%(141,859) | 42.9%(109,261) | D+12.8 | D+17.8 |
Source: Official state election returns via MIT Election Data + Science Lab
Senate Elections
Senate Results
| Year | Democrat | Republican | Margin | Swing |
|---|---|---|---|---|
| 2018 | 63.0%(168,679) | 0.0%(0) | D+63.0 | D+8.5 |
| 2012 | 77.2%(213,503) | 22.8%(62,979) | D+54.4 | R+0.2 |
| 2006 | 74.8%(152,082) | 20.2%(41,043) | D+54.6 | D+19.7 |
| 2000 | 64.8%(165,216) | 29.9%(76,273) | D+34.9 | D+0.6 |
| 1994 | 64.2%(136,686) | 29.9%(63,702) | D+34.3 | R+5.1 |
| 1992 | 67.3%(181,990) | 27.9%(75,470) | D+39.4 | D+33.5 |
| 1988 | 51.1%(125,724) | 45.2%(111,187) | D+5.9 | D+8.1 |
| 1982 | 47.0%(98,862) | 49.1%(103,493) | R+2.2 | D+0.8 |
| 1976 | 46.5%(105,541) | 49.6%(112,445) | R+3.0 | R+17.9 |
| 1970 | 56.6%(113,844) | 41.8%(84,054) | D+14.8 | D+16.1 |
Source: Official state election returns via MIT Election Data + Science Lab
Governor Elections
Governor Results
| Year | Democrat | Republican | Margin | Swing |
|---|---|---|---|---|
| 2018 | 75.2%(213,282) | 24.8%(70,242) | D+50.5 | 0.0 |
| 2014 | 75.2%(120,280) | 24.8%(39,615) | D+50.5 | D+15.9 |
| 2010 | 65.7%(145,970) | 31.1%(69,212) | D+34.5 | D+34.2 |
| 2006 | 47.4%(97,092) | 47.1%(96,478) | D+0.3 | R+27.8 |
| 2002 | 58.0%(99,803) | 29.9%(51,497) | D+28.1 | R+11.9 |
| 1998 | 68.4%(142,144) | 28.5%(59,249) | D+39.9 | D+38.3 |
| 1994 | 49.2%(106,391) | 47.6%(102,989) | D+1.6 | R+13.4 |
| 1990 | 55.4%(109,963) | 40.5%(80,253) | D+15.0 | D+40.6 |
| 1986 | 36.2%(71,329) | 61.8%(121,910) | R+25.7 | R+29.8 |
| 1982 | 50.5%(108,374) | 46.4%(99,527) | D+4.1 | R+17.8 |
Source: Official state election returns via MIT Election Data + Science Lab