Shirrells, San Bernardino, CA Political Map | Democrat & Republican Areas in Shirrells

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

Shirrells is a Democratic stronghold. About 77% of voters here vote Democratic and 23% Republican.

 

About 27% of adults in Shirrells typically vote, below the U.S. average of about 62%. Among adults in Shirrells, ~21% vote Democratic, ~6% Republican, and ~73% don't vote. The map below shows estimated turnout by block group.

How Shirrells compares

Among neighborhoods within 5 miles, Shirrells is the most Democratic-leaning.

Shirrells runs about 33 points more Democratic than California as a whole.

Politics vary noticeably by block within Shirrells. The east side is the most Democratic-leaning (D+59) and the southeast side is the least Democratic-leaning (D+40), a spread of about 19 points.

Why Shirrells 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 Shirrells, not a ranked or complete list of what matters most.

Dense areas vote Democratic. More than 99% of residents in Shirrells live in densely developed areas, about 64 points above the U.S. average of 36%.

Population density and Democratic lean

Places with high population density tend to lean Democratic; Shirrells, San Bernardino, CA sits in the top quarter nationally on this measure.

Why turnout in Shirrells looks the way it does

Areas with limited routine healthcare access turn out at lower rates. Shirrells 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 47%, about 15 points below the California average of 62%. High food insecurity lines up with lower turnout, and about 37% of adults in Shirrells report food insecurity, above 91% of neighborhoods. High-crime urban areas turn out at lower rates, and Shirrells sits in the top 15% on a violent-crime measure. 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.