San Luis Obispo leans heavily Democratic by roughly 38 points: about 69% of voters vote Democratic and 31% Republican.
About 58% of adults in San Luis Obispo typically vote, near the U.S. average of about 62%. Among adults in San Luis Obispo, ~40% vote Democratic, ~18% Republican, and ~42% don't vote. The map below shows estimated turnout by block group.
How San Luis Obispo compares
Among cities within 25 miles, San Luis Obispo is the most Democratic-leaning.
San Luis Obispo runs about 19 points more Democratic than California as a whole.
Politics vary noticeably by neighborhood within San Luis Obispo. The north side is the most Democratic-leaning (D+48) and the southwest side is the least Democratic-leaning (D+19), a spread of about 29 points.
Why San Luis Obispo leans the way it does
This analysis examined 14,881 data points per city to find what predicts political lean and turnout. The items below are a few correlations that stood out for San Luis Obispo, not a ranked or complete list of what matters most.
Dense areas vote Democratic. About 66% of residents in San Luis Obispo live in densely developed areas, about 30 points above the U.S. average of 36%. High college attainment predicts Democratic voting, and San Luis Obispo sits in the top quarter (about 50%, above 94% of cities). A high never-married share predicts Democratic voting, and about 59% of adults in San Luis Obispo have never been married, in the top fraction of cities.
Walkability and Democratic lean
Places with a highly walkable street grid tend to lean Democratic; San Luis Obispo, CA sits in the top tenth nationally on this measure. A walkable street grid does not change how people vote; it mostly reflects how urban a place is.
Why turnout in San Luis Obispo looks the way it does
Renters vote less often than owners. About 56% of households in San Luis Obispo rent, about 31 points above the U.S. average of 25%. Crowded housing lines up with lower turnout, and about 4% of homes in San Luis Obispo have more than one occupant per room, above 81% of cities. Learn more about the findings and methodology on the political spectrum map.
Nearby Cities
- Avila Beach, CA D+19
- Shell Beach, CA D+16
- Pismo Beach, CA D+14
- Los Osos, CA D+21
- Garden Farms, CA R+22
- Grover Beach, CA D+10
- Halcyon, CA R+9
- Santa Margarita, CA R+23
- Arroyo Grande, CA D+3
- Morro Bay, CA D+16
Cities with Similar Populations
- Castro Valley, CA D+33
- Lorain, OH D+14
- Waltham, MA D+43
- Casa Grande, AZ R+14
- Arcadia, CA D+14
- Hanford, CA R+15
- Joplin, MO R+33
- North Richland Hills, TX R+21
- Wilkes-Barre, PA D+4
- The Villages, FL R+29
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.