County record · fips 06013 · California
Contra CostaCA
Democratic ×10 since 1988all 40 elections, 1868–2024
The Long Record
40 elections against the California and national vote
2024 result
D+39.3
won by Democrats
Record since first cycle
22–18
Dem–Rep two-party wins
Voted with the winner
29/40
73% of its elections
Closest election
1976
R+1.1
this countyCalifornianational (official)dot colour = two-party winner · hollow = tie or unknown total · click a dot to open that election
The Biggest Swings
Cycle-over-cycle change in the two-party margin, in points
| Election | Swing | Toward |
|---|---|---|
| 1912 | +132.8 pts | Democrats |
| 1916 | -94.6 pts | Republicans |
| 1872 | +70.3 pts | Democrats |
| 1876 | -68.1 pts | Republicans |
| 1928 | +56.2 pts | Democrats |
Who Lives Here
Census & ACS county profile, 2024
Population
1,165,012
College (BA+)
45%
Median income
$127,229
2024 dollars
Non-white
62%
Rural
1%
Age 65+
17%
Interpolated between Census/ACS anchors; income CPI-deflated to 2024. Demographics begin in 2000 — earlier cycles have returns only.