Rosemont leans slightly Republican by roughly 10 points: about 45% of voters vote Democratic and 55% Republican.
About 59% of adults in Rosemont typically vote, near the U.S. average of about 62%. Among adults in Rosemont, ~27% vote Democratic, ~32% Republican, and ~41% don't vote. The map below shows estimated turnout by block group.
How Rosemont compares
Among cities within 25 miles, Rosemont leans more Republican than 148 of 162 neighbors.
Rosemont runs about 20 points more Republican than Illinois as a whole. Illinois leans Democratic overall, while Rosemont is one of the few Republican-leaning pockets.
Politics vary noticeably by neighborhood within Rosemont. The northwest side runs the most Democratic (D+4) and the west side runs the most Republican (R+31), a spread of about 35 points.
Why Rosemont 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 Rosemont, not a ranked or complete list of what matters most.
Rosemont votes Republican even though it is densely developed (more than 99%, far above the Illinois average of 33%). State and regional patterns outweigh the Democratic lean that density usually predicts here. Rosemont runs against the grain of Illinois, 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 Rosemont, IL does.
Why turnout in Rosemont looks the way it does
Areas with limited routine healthcare access turn out at lower rates. Rosemont 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 79% of households in Rosemont rent, compared to around 30% in nearby cities. Crowded housing lines up with lower turnout, and about 9% of homes in Rosemont have more than one occupant per room, above 95% of cities. Learn more about the findings and methodology on the political spectrum map.
Nearby Cities
- Park Ridge, IL D+13
- Schiller Park, IL R+13
- Des Plaines, IL D+7
- Norridge, IL R+21
- Niles, IL R+7
- Harwood Heights, IL R+13
- Franklin Park, IL D+6
- Bensenville, IL D+8
- River Grove, IL R+4
- Mount Prospect, IL D+12
Cities with Similar Populations
- Bishop, GA R+46
- Roseville, OH R+57
- Woodbine, GA R+37
- Cassatt, SC R+40
- Red Bay, AL R+70
- Mabton, WA D+3
- McKean, PA R+30
- Olney, TX R+64
- Dolores, CO R+34
- White Haven, PA R+35
All Local Stats
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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.