San Luis Obispo County, CA Political Map | Democrat & Republican Areas in San Luis Obispo County

By the BestNeighborhood data science team. Last updated May 2026.

San Luis Obispo County leans slightly Democratic by roughly 8 points: about 54% of voters vote Democratic and 46% Republican.

 

About 68% of adults in San Luis Obispo County typically vote, above the U.S. average of about 62%. Among adults in San Luis Obispo County, ~37% vote Democratic, ~31% Republican, and ~32% don't vote. The map below shows estimated turnout by block group.

How San Luis Obispo County compares

San Luis Obispo County runs about 13 points more Republican than California as a whole.

Politics vary noticeably by city within San Luis Obispo County. The south side runs the most Democratic (D+24) and the northeast side runs the most Republican (R+41), a spread of about 66 points.

Why San Luis Obispo County leans the way it does

This analysis examined 14,881 data points per county to find what predicts political lean and turnout. The items below are a few correlations that stood out for San Luis Obispo County, not a ranked or complete list of what matters most.

Dense areas vote Democratic. About 61% of residents in San Luis Obispo County live in densely developed areas, about 25 points above the U.S. average of 36%. High college attainment predicts Democratic voting, and San Luis Obispo County sits in the top quarter (about 40%, above 91% of counties). A high never-married share predicts Democratic voting, and about 35% of adults in San Luis Obispo County have never been married, above 83% of counties.

Walkability and Democratic lean

Places with a highly walkable street grid tend to lean Democratic; San Luis Obispo County, 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 County looks the way it does

Areas with strong routine healthcare access turn out at higher rates. San Luis Obispo County is in the top quarter nationally for routine-care measures such as insurance coverage, preventive screenings, and dental visits. The dental-visit rate here is about 67%, about 7 points above the U.S. average of 60%. Learn more about the findings and methodology on the political spectrum map.

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.