Eureka leans Republican by roughly 24 points: about 38% of voters vote Democratic and 62% Republican.
About 72% of adults in Eureka typically vote, above the U.S. average of about 62%. Among adults in Eureka, ~27% vote Democratic, ~45% Republican, and ~28% don't vote. The map below shows estimated turnout by block group.
How Eureka compares
Among cities within 25 miles, Eureka leans more Republican than 89 of 149 neighbors.
Eureka runs about 6 points more Republican than Missouri as a whole.
Politics vary noticeably by neighborhood within Eureka. The southeast side is the most Republican-leaning (R+39) and the northwest side is the least Republican-leaning (R+17), a spread of about 21 points.
Why Eureka 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 Eureka, not a ranked or complete list of what matters most.
Eureka votes Republican even though it is densely developed (about 39%, well above the Missouri average of 22%). State and regional patterns outweigh the Democratic lean that density usually predicts here.
High-school completion, uninsured rate, and voter turnout
Places that combine high-school-completion-heavy adults and a low uninsured rate tend to turn out at a higher rate, as Eureka, MO does.
Why turnout in Eureka looks the way it does
Areas with strong routine healthcare access turn out at higher rates. Eureka 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%. High high-school completion lines up with higher turnout, and about 96% of adults in Eureka have completed high school, above 84% of cities. Learn more about the findings and methodology on the political spectrum map.
Nearby Cities
- Times Beach, MO R+29
- Parkdale, MO R+40
- Byrnes Mill, MO R+40
- Pacific, MO R+39
- Grover, MO R+10
- High Ridge, MO R+36
- Wildwood, MO R+16
- Ellisville, MO Even
- Scotsdale, MO R+45
Cities with Similar Populations
- Grand Ledge, MI R+4
- Wauconda, IL Even
- Quincy, FL D+45
- Bethlehem, GA R+32
- Merrill, WI R+27
- North Reading, MA D+9
- Valle Vista, CA R+15
- Marco Island, FL R+31
- Prospect Heights, IL D+9
- Glenmont, MD D+51
All Local Stats
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Sources and methodology
Precinct-level voting records used to fit the model come from Missouri 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.