Jackson County leans heavily Republican by roughly 36 points: about 32% of voters vote Democratic and 68% Republican.
About 90% of adults in Jackson County typically vote, above the U.S. average of about 62%. Among adults in Jackson County, ~29% vote Democratic, ~61% Republican, and ~10% don't vote. The map below shows estimated turnout by block group.
How Jackson County compares
Among counties within 50 miles, Jackson County leans more Republican than 12 of 13 neighbors.
Jackson County runs about 22 points more Republican than Iowa as a whole.
Politics vary noticeably by city within Jackson County. The east side is the most Republican-leaning (R+47) and the southwest side is the least Republican-leaning (R+23), a spread of about 24 points.
Why Jackson County leans the way it does
Density, race composition, education, and family structure all sit close to their national averages in Jackson County. The lean here lands roughly where demographic data alone would predict.
Cancer-screening access and voter turnout
Places with high colon-cancer-screening access tend to turn out at a higher rate; Jackson County, IA sits in the top tenth nationally on this measure. Cancer screening does not drive turnout; it reflects income, insurance, and healthcare access.
Why turnout in Jackson County looks the way it does
Areas with strong routine healthcare access turn out at higher rates. Jackson County 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%. Homeowners vote more often than renters, and about 81% of households in Jackson County own their home, above 82% of counties. High high-school completion lines up with higher turnout, and about 94% of adults in Jackson County have completed high school, above 87% of counties. Learn more about the findings and methodology on the political spectrum map.
Nearby Counties
- Jo Daviess County, IL R+18
- Clinton County, IA R+21
- Dubuque County, IA R+12
- Carroll County, IL R+34
- Jones County, IA R+27
- Cedar County, IA R+34
- Scott County, IA D+5
- Lafayette County, WI R+31
- Rock Island County, IL D+12
- Whiteside County, IL R+20
Counties with Similar Populations
- Spencer County, KY R+56
- Langlade County, WI R+35
- Chaffee County, CO D+6
- Adair County, OK R+54
- Fayette County, IA R+30
- Macon County, AL D+57
- Freestone County, TX R+56
- East Feliciana Parish, LA R+24
- Los Alamos County, NM D+27
- Wayne County, KY R+65
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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.