South Mountain leans heavily Democratic by roughly 34 points: about 67% of voters vote Democratic and 33% Republican.
About 48% of adults in South Mountain typically vote, below the U.S. average of about 62%. Among adults in South Mountain, ~32% vote Democratic, ~16% Republican, and ~52% don't vote. The map below shows estimated turnout by block group.
How South Mountain compares
South Mountain sits in a sparsely populated area with few comparable neighborhoods nearby.
South Mountain runs about 40 points more Democratic than Arizona as a whole. Arizona leans Republican overall, while South Mountain is one of the few Democratic-leaning pockets.
Politics vary noticeably by block within South Mountain. The north side is the most Democratic-leaning (D+44) and the southwest side is the least Democratic-leaning (D+25), a spread of about 19 points.
Why South Mountain 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 Mountain, not a ranked or complete list of what matters most.
South Mountain votes against the grain of Arizona. Arizona leans Republican overall, while South Mountain runs about 40 points more Democratic.
Population density and Democratic lean
Places with high population density tend to lean Democratic; South Mountain, Phoenix, AZ sits above the national average on this measure.
Why turnout in South Mountain looks the way it does
Areas with limited routine healthcare access turn out at lower rates. South Mountain is in the bottom quarter nationally for routine-care measures such as insurance coverage, preventive screenings, and dental visits. The dental-visit rate here is about 49%, about 6 points below the Arizona average of 54%. High food insecurity lines up with lower turnout, and about 30% of adults in South Mountain report food insecurity, above 82% of neighborhoods. Learn more about the findings and methodology on the political spectrum map.
Nearby Neighborhoods
Neighborhoods with Similar Populations
- South Side, Corpus Christi, TX R+5
- West San Jose, San Jose, CA D+31
- Southeastern Denver, Denver, CO D+47
- Koreatown, Los Angeles, CA D+45
- Corona, Queens, NY D+14
- Southwest, Anaheim, CA D+10
- Wakefield-Williamsbridge, Bronx, NY D+73
- Bushwick, Brooklyn, NY D+61
- Westlake, Los Angeles, CA D+41
- North, Houston, TX D+26
Sources and methodology
Precinct-level voting records used to fit the model come from Arizona 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.