Linn County leans slightly Democratic by roughly 6 points: about 53% of voters vote Democratic and 47% Republican.
About 80% of adults in Linn County typically vote, above the U.S. average of about 62%. Among adults in Linn County, ~42% vote Democratic, ~38% Republican, and ~20% don't vote. The map below shows estimated turnout by block group.
How Linn County compares
Among counties within 50 miles, Linn County leans more Democratic than 10 of 11 neighbors.
Linn County runs about 20 points more Democratic than Iowa as a whole. Iowa leans Republican overall, while Linn County is one of the few Democratic-leaning pockets.
Politics vary noticeably by city within Linn County. The south side runs the most Democratic (D+14) and the northwest side runs the most Republican (R+24), a spread of about 38 points.
Why Linn 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 Linn County, not a ranked or complete list of what matters most.
Dense areas vote Democratic. About 71% of residents in Linn County live in densely developed areas, about 35 points above the U.S. average of 36%. High college attainment predicts Democratic voting, and Linn County sits in the top quarter (about 34%, above 84% of counties). Linn County runs against the grain of Iowa, a Democratic-leaning pocket in a Republican-leaning state.
Preventive-care access and voter turnout
Places with strong routine preventive-care access tend to turn out at a higher rate; Linn County, IA sits in the top 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 Linn County looks the way it does
Areas with strong routine healthcare access turn out at higher rates. Linn 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 68%, about 8 points above the U.S. average of 60%. High high-school completion lines up with higher turnout, and about 95% of adults in Linn County have completed high school, above 90% of counties. Learn more about the findings and methodology on the political spectrum map.
Nearby Counties
- Benton County, IA R+36
- Johnson County, IA D+36
- Jones County, IA R+27
- Iowa County, IA R+38
- Cedar County, IA R+34
- Delaware County, IA R+39
- Buchanan County, IA R+36
- Washington County, IA R+33
- Tama County, IA R+25
- Muscatine County, IA R+16
Counties with Similar Populations
- Berkeley County, SC R+13
- Canyon County, ID R+40
- Barnstable County, MA D+20
- Montgomery County, AL D+38
- Baldwin County, AL R+53
- Mahoning County, OH Even
- Oneida County, NY R+13
- Lake County, OH R+11
- Gaston County, NC R+18
- Hinds County, MS D+52
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.