Old Marissa, IL Political Map | Democrat & Republican Areas in Old Marissa

Old Marissa is a Republican stronghold. About 22% of voters here vote Democratic and 78% Republican.

 
Old Marissa, IL block-group political-lean map
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About 74% of adults in Old Marissa typically vote, above the U.S. average of about 62%. Among adults in Old Marissa, ~16% vote Democratic, ~58% Republican, and ~26% don't vote. The map below shows estimated turnout by block group.

Old Marissa, IL block-group voter-turnout map
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How Old Marissa compares

Among cities within 25 miles, Old Marissa leans more Republican than 42 of 72 neighbors.

Old Marissa runs about 66 points more Republican than Illinois as a whole. Illinois leans Democratic overall, while Old Marissa is one of the few Republican-leaning pockets.

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

Old Marissa votes against the grain of Illinois. Illinois leans Democratic overall, while Old Marissa runs about 66 points more Republican. Low college attainment predicts Republican voting, and Old Marissa sits in the bottom quarter (about 11%, below 89% of cities).

High-school completion and voter turnout

Places with high-school-completion-heavy adults tend to turn out at a higher rate; Old Marissa, IL sits in the top tenth nationally on this measure.

Why turnout in Old Marissa looks the way it does

Areas with high high-school completion turn out at higher rates. About 98% of adults in Old Marissa have completed high school, about 6 points above the Illinois average of 92%. Learn more about the findings and methodology on the political spectrum map.

Cities with Similar Populations

Sources and methodology

Precinct-level voting records used to fit the model come from Illinois State Board of 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.