San Mateo, California — Presidential Election Results
San Mateo, California has voted Democratic in 7 of the last 7 presidential elections on record (2000–2024). In 2024, it was 31.3 pts more Dem. than California overall.
Jump to year: 2000 · 2004 · 2008 · 2012 · 2016 · 2020 · 2024
Full Election History, 2000–2024
| Year | Winner | Party | Votes | Vote Share | Margin | Total Votes Cast | Swing | Vs. California |
|---|---|---|---|---|---|---|---|---|
| 2000 | Al Gore | Democratic | 166,757 | 64.3% | 33.3 pts (86,461 votes) | 259,399 | — | 22.6 pts more Dem. |
| 2004 | John Kerry | Democratic | 197,922 | 69.7% | 40.3 pts (114,607 votes) | 284,077 | +5.8 pts | 30.7 pts more Dem. |
| 2008 | Barack Obama | Democratic | 222,826 | 73.5% | 48.7 pts (147,769 votes) | 303,292 | +8.9 pts | 25.0 pts more Dem. |
| 2012 | Barack Obama | Democratic | 206,085 | 72.1% | 46.7 pts (133,329 votes) | 285,720 | -1.8 pts | 24.1 pts more Dem. |
| 2016 | Hillary Clinton | Democratic | 237,882 | 75.7% | 57.2 pts (179,953 votes) | 314,384 | +13.0 pts | 28.6 pts more Dem. |
| 2020 | Joseph R Biden Jr | Democratic | 291,496 | 77.9% | 57.7 pts (215,912 votes) | 374,251 | -2.0 pts | 29.0 pts more Dem. |
| 2024 | Kamala D Harris | Democratic | 242,957 | 73.5% | 50.3 pts (166,341 votes) | 330,510 | -6.8 pts | 31.3 pts more Dem. |
Population Context
Total Census Bureau population estimate for the county that year, and recorded votes as a share of that total population. This is a population-based figure, not a turnout rate against eligible or registered voters, which this site does not calculate.
| Year | County Population | Votes Cast (% of Population) |
|---|---|---|
| 2000 | 707,820 | 36.6% of population |
| 2004 | 690,161 | 41.2% of population |
| 2008 | 703,830 | 43.1% of population |
| 2012 | 739,224 | 38.7% of population |
| 2016 | 767,906 | 40.9% of population |
| 2020 | 762,727 | 49.1% of population |
| 2024 | 742,893 | 44.5% of population |
Trend
Between 2000 and 2024, the two-party presidential margin in San Mateo shifted 17.1 points toward the Democratic candidate, based on recorded county returns. This reflects the vote totals in this dataset only; no claim is made here about the causes of that shift.
Margin Over Time
Democratic candidate's margin (percentage points, two-party vote share). Positive values favor the Democratic candidate; negative values favor the Republican candidate.
Bellwether Status
San Mateo has matched the national popular winner in 3 of the last 7 presidential elections (43%), and California's own statewide winner in 7 of 7 (100%). Compare every county on the bellwether counties page.
Related Pages
Other California Counties
Frequently Asked Questions
How has San Mateo voted in presidential elections since 2000?
Since 2000, San Mateo has voted Democratic in 7 of 7 recorded presidential elections and Republican in 0 of 7, based on county-level returns through 2024.
What was the closest presidential election in San Mateo?
San Mateo's closest recorded margin was in 2000, when Al Gore (Democratic) won by 35.0 points (86,461 votes) out of 259,399 total votes cast.
Has San Mateo ever flipped between parties?
Not in the 2000-2024 record on this page -- San Mateo has voted for the same party in every recorded presidential election in that span.
What is the largest presidential election margin recorded in San Mateo?
The widest margin on record for San Mateo was in 2016, when Hillary Clinton (Democratic) won by 60.8 points.
How many votes were cast in San Mateo relative to its population?
In 2024, 330,510 votes were recorded in San Mateo against a total population of 742,893 (44.5% of the total population). This is a population-based figure, not a turnout rate against eligible or registered voters, which this site does not calculate.
Is San Mateo a presidential bellwether county?
San Mateo has matched the national popular winner in 3 of the last 7 presidential elections (43%), and California's own statewide winner in 7 of 7 (100%).