Markham, IL Political Map | Democrat & Republican Areas in Markham

Markham is a Democratic stronghold. About 86% of voters here vote Democratic and 14% Republican.

 
Markham, IL block-group political-lean map
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About 61% of adults in Markham typically vote, near the U.S. average of about 62%. Among adults in Markham, ~52% vote Democratic, ~9% Republican, and ~39% don't vote. The map below shows estimated turnout by block group.

Markham, IL block-group voter-turnout map
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How Markham compares

Among cities within 25 miles, Markham leans more Democratic than 123 of 142 neighbors.

Markham runs about 61 points more Democratic than Illinois as a whole.

Politics vary noticeably by neighborhood within Markham. The northeast side is the most Democratic-leaning (D+83) and the west side is the least Democratic-leaning (D+52), a spread of about 31 points.

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

Dense areas vote Democratic. About 92% of residents in Markham live in densely developed areas, about 55 points above the U.S. average of 36%. A high never-married share predicts Democratic voting, and about 52% of adults in Markham have never been married, above 98% of cities.

Preventive-care access and voter turnout

Places with limited routine preventive-care access tend to turn out at a lower rate; Markham, IL sits in the bottom tenth nationally on this measure. Dental visits do not drive turnout; the rate reflects income, insurance, and healthcare access, which line up with who votes.

Why turnout in Markham looks the way it does

Areas with limited routine healthcare access turn out at lower rates. Markham 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 48%, about 15 points below the Illinois average of 63%. High food insecurity lines up with lower turnout, and about 36% of adults in Markham report food insecurity, above 98% 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 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.