South Los Altos leans heavily Democratic by roughly 38 points: about 69% of voters vote Democratic and 31% Republican.
About 71% of adults in South Los Altos typically vote, above the U.S. average of about 62%. Among adults in South Los Altos, ~49% vote Democratic, ~22% Republican, and ~29% don't vote. The map below shows estimated turnout by block group.
How South Los Altos compares
Among neighborhoods within 5 miles, South Los Altos leans more Democratic than 7 of 17 neighbors.
South Los Altos runs about 18 points more Democratic than California as a whole.
Politics vary noticeably by block within South Los Altos. The northwest side is the most Democratic-leaning (D+43) and the southeast side is the least Democratic-leaning (D+32), a spread of about 10 points.
Why South Los Altos 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 South Los Altos, not a ranked or complete list of what matters most.
Areas with high college attainment vote Democratic. About 84% of adults in South Los Altos hold a bachelor's degree, about 56 points above the U.S. average of 28%. Dense areas vote Democratic, and South Los Altos sits in the top fifth on density (more than 99%, above 89% of neighborhoods).
Park access and Democratic lean
Places with heavy park coverage tend to lean Democratic; South Los Altos, Los Altos, CA sits in the top quarter nationally on this measure. Park access does not change how people vote; it tends to track denser, higher-income areas.
Why turnout in South Los Altos looks the way it does
Areas with strong routine healthcare access turn out at higher rates. South Los Altos 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 76%, about 16 points above the U.S. average of 60%. High high-school completion lines up with higher turnout, and about 98% of adults in South Los Altos have completed high school, above 85% of neighborhoods. Learn more about the findings and methodology on the political spectrum map.
Nearby Neighborhoods
- Sunnyvale West, Sunnyvale, CA D+37
- Martens-Carmelita, Mountain View, CA D+38
- Cuesta Park, Mountain View, CA D+40
- Heritage District, Sunnyvale, CA D+43
- Old Mountain View, Mountain View, CA D+60
- Whisman Station, Mountain View, CA D+45
- Birdland Neighbors, Sunnyvale, CA D+36
- Ponderosa Park, Sunnyvale, CA D+34
- Rancho Rinconada, Cupertino, CA D+33
- Lowlanders, Sunnyvale, CA D+42
Neighborhoods with Similar Populations
- Southeast Como, Minneapolis, MN D+66
- Tippecanoe, Milwaukee, WI D+32
- Diamond Lake, Minneapolis, MN D+62
- Michigan Park, Washington, DC D+86
- Natomas Creek, Sacramento, CA D+34
- Cascade View, Everett, WA D+14
- Town of Lake, Milwaukee, WI D+16
- Meadow Hills, Aurora, CO D+33
- Italian Bowery, Chicago, IL D+82
- Somerset, Glendale, CA D+23
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.