Jo Daviess County leans Republican by roughly 18 points: about 41% of voters vote Democratic and 59% Republican.
About 83% of adults in Jo Daviess County typically vote, above the U.S. average of about 62%. Among adults in Jo Daviess County, ~34% vote Democratic, ~49% Republican, and ~17% don't vote. The map below shows estimated turnout by block group.
How Jo Daviess County compares
Among counties within 50 miles, Jo Daviess County leans more Republican than 4 of 10 neighbors.
Jo Daviess County runs about 29 points more Republican than Illinois as a whole. Illinois leans Democratic overall, while Jo Daviess County is one of the few Republican-leaning pockets.
Politics vary noticeably by city within Jo Daviess County. The west side runs the most Democratic (D+5) and the east side runs the most Republican (R+40), a spread of about 45 points.
Why Jo Daviess County leans the way it does
This analysis examined 14,881 data points per county to find what predicts political lean and turnout. The items below are a few correlations that stood out for Jo Daviess County, not a ranked or complete list of what matters most.
Jo Daviess County votes against the grain of Illinois. Illinois leans Democratic overall, while Jo Daviess County runs about 29 points more Republican.
Preventive-care access and voter turnout
Places with strong routine preventive-care access tend to turn out at a higher rate; Jo Daviess County, IL sits in the top quarter 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 Jo Daviess County looks the way it does
Homeowners vote more often than renters. About 81% of households in Jo Daviess County own their home, about 6 points above the U.S. average of 75%. Learn more about the findings and methodology on the political spectrum map.
Nearby Counties
- Lafayette County, WI R+31
- Jackson County, IA R+35
- Dubuque County, IA R+12
- Carroll County, IL R+34
- Grant County, WI R+23
- Stephenson County, IL R+14
- Clinton County, IA R+21
- Iowa County, WI R+11
- Green County, WI R+11
- Jones County, IA R+27
Counties with Similar Populations
- Martin County, NC R+4
- Putnam County, GA R+26
- Anson County, NC Even
- Houston County, TX R+41
- Randolph County, AL R+59
- Seward County, KS R+27
- Henry County, MO R+54
- Limestone County, TX R+40
- Sabine Parish, LA R+55
- Grant Parish, LA R+77
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.