Gridley, CA Political Map | Democrat & Republican Areas in Gridley

Gridley leans Republican by roughly 30 points: about 35% of voters vote Democratic and 65% Republican.

 
Gridley, CA block-group political-lean map
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About 51% of adults in Gridley typically vote, below the U.S. average of about 62%. Among adults in Gridley, ~18% vote Democratic, ~33% Republican, and ~49% don't vote. The map below shows estimated turnout by block group.

Gridley, CA block-group voter-turnout map
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How Gridley compares

Among cities within 25 miles, Gridley leans more Republican than 17 of 39 neighbors.

Gridley runs about 50 points more Republican than California as a whole. California leans Democratic overall, while Gridley is one of the few Republican-leaning pockets.

Politics vary noticeably by neighborhood within Gridley. The east side is the most Republican-leaning (R+41) and the north side is the least Republican-leaning (R+23), a spread of about 19 points.

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

Gridley votes Republican even though it is densely developed (about 56%, about 19 points above the U.S. average of 36%). State and regional patterns outweigh the Democratic lean that density usually predicts here. Gridley runs against the grain of California, a Republican-leaning pocket in a Democratic-leaning state.

High-school completion, developed land, and voter turnout

Places that combine low high-school-completion share and a heavily developed built environment tend to turn out at a lower rate, as Gridley, CA does.

Why turnout in Gridley looks the way it does

Areas with limited routine healthcare access turn out at lower rates. Gridley is in the bottom quarter nationally for routine-care measures such as insurance coverage, preventive screenings, and dental visits. Renters vote less often than owners, and about 43% of households in Gridley rent, compared to around 26% in nearby cities. High food insecurity lines up with lower turnout, and about 23% of adults in Gridley report food insecurity, above 87% of cities. Learn more about the findings and methodology on the political spectrum map.

Cities with Similar Populations

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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.