Marengo, IA Political Map | Democrat & Republican Areas in Marengo

Marengo leans heavily Republican by roughly 36 points: about 32% of voters vote Democratic and 68% Republican.

 
Marengo, IA block-group political-lean map
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About more than 99% of adults in Marengo typically vote, above the U.S. average of about 62%. Among adults in Marengo, ~33% vote Democratic, ~70% Republican, and ~-3% don't vote. The map below shows estimated turnout by block group.

Marengo, IA block-group voter-turnout map
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How Marengo compares

Among cities within 25 miles, Marengo leans more Republican than 21 of 48 neighbors.

Marengo runs about 23 points more Republican than Iowa as a whole.

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

Areas with a high white share and below-average college attainment vote Republican. In Marengo, about 95% of residents are non-Hispanic white, about 23 points above the U.S. average of 72%; about 14% of adults hold a bachelor's degree, about 11 points below the Iowa average of 24%. Dense places usually vote Democratic, but Marengo runs against that pattern.

Population density and Democratic lean

Places with high population density tend to lean Democratic; Marengo, IA sits in the top quarter nationally on this measure.

Why turnout in Marengo looks the way it does

Areas with strong routine healthcare access turn out at higher rates. Marengo 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 69%, about 9 points above the U.S. average of 60%. 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 Iowa 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.