Brea-Olinda is a true toss-up. About 49% of voters here vote Democratic and 51% Republican.
About 69% of adults in Brea-Olinda typically vote, above the U.S. average of about 62%. Among adults in Brea-Olinda, ~34% vote Democratic, ~35% Republican, and ~31% don't vote. The map below shows estimated turnout by block group.
How Brea-Olinda compares
Among neighborhoods within 5 miles, Brea-Olinda sits roughly in the middle of the political spectrum, with 3 neighbors leaning further in the place's direction and 0 leaning the other way.
Brea-Olinda runs about 23 points more Republican than California as a whole. California leans Democratic overall, while Brea-Olinda sits closer to the political middle.
Politics vary noticeably by block within Brea-Olinda. The northeast side runs the most Democratic (Even) and the northwest side runs the most Republican (R+11), a spread of about 11 points.
Why Brea-Olinda leans the way it does
This analysis examined 14,881 data points per neighborhood to find what predicts political lean and turnout. The items below are a few correlations that stood out for Brea-Olinda, not a ranked or complete list of what matters most.
Brea-Olinda votes against the grain of California. California leans Democratic overall, while Brea-Olinda runs about 23 points more Republican.
Adult arthritis and voter turnout
Places with a low adult-arthritis rate tend to turn out at a higher rate; Brea-Olinda, Brea, CA sits in the bottom quarter nationally on this measure. Arthritis does not drive turnout; it reflects the age and health profile of an area.
Why turnout in Brea-Olinda looks the way it does
Turnout in Brea-Olinda sits close to the national pattern. Routine healthcare access, homeownership, education, and food security all land near their national averages here. Learn more about the findings and methodology on the political spectrum map.
Nearby Neighborhoods
- La Habra City, La Habra, CA D+7
- Downtown Fullerton, Fullerton, CA D+23
- Northeast, Anaheim, CA D+16
- Lowell, La Habra, CA Even
- The Colony, Anaheim, CA D+24
- Walnut Valley, Diamond Bar, CA D+9
- Southeast, Anaheim, CA D+19
- Northwest, Anaheim, CA D+15
- Anaheim Hills, Anaheim, CA R+8
- SouthWest Anaheim, Anaheim, CA D+11
Neighborhoods with Similar Populations
Sources and methodology
Precinct-level voting records used to fit the model come from California Secretary of State, Elections, distributed by the Voting and Election Science Team. Demographic inputs come from the U.S. Census Bureau (ACS 5-year estimates and the 2020 Decennial Census). Health and environmental inputs come from the CDC (PLACES and the Environmental Justice Index). Land cover comes from the USGS and EPA. Election-day and lead-up weather come from PRISM 4km daily grids and the NOAA Global Historical Climatology Network. Mail-voting and election-administration patterns come from the MIT Election Lab's Survey of the Performance of American Elections. Block-group crime detail comes from CrimeGrade. Internet data and modeling support provided by ISPreports.org.
Modeling and analysis by the BestNeighborhood data science team. Full methodology and findings: political spectrum map.
Methodology reviewed by the BestNeighborhood data team. Last updated May 2026.