Boone County leans Republican by roughly 24 points: about 38% of voters vote Democratic and 62% Republican.
About 89% of adults in Boone County typically vote, above the U.S. average of about 62%. Among adults in Boone County, ~34% vote Democratic, ~55% Republican, and ~11% don't vote. The map below shows estimated turnout by block group.
How Boone County compares
Among counties within 50 miles, Boone County leans more Republican than 6 of 14 neighbors.
Boone County runs about 11 points more Republican than Iowa as a whole.
Politics vary noticeably by city within Boone County. The northwest side is the most Republican-leaning (R+40) and the east side is the least Republican-leaning (R+16), a spread of about 24 points.
Why Boone County leans the way it does
Density, race composition, education, and family structure all sit close to their national averages in Boone 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; Boone County, IA sits in the top quarter nationally on this measure. Cancer screening does not drive turnout; it reflects income, insurance, and healthcare access.
Why turnout in Boone County looks the way it does
Areas with strong routine healthcare access turn out at higher rates. Boone 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 70%, about 10 points above the U.S. average of 60%. Homeowners vote more often than renters, and about 81% of households in Boone County own their home, above 81% of counties. High high-school completion lines up with higher turnout, and about 95% of adults in Boone County have completed high school, above 92% of counties. Learn more about the findings and methodology on the political spectrum map.
Nearby Counties
- Story County, IA D+14
- Greene County, IA R+39
- Hamilton County, IA R+34
- Dallas County, IA R+7
- Polk County, IA D+12
- Webster County, IA R+22
- Guthrie County, IA R+41
- Hardin County, IA R+40
- Calhoun County, IA R+48
- Warren County, IA R+24
Counties with Similar Populations
- Juneau County, WI R+31
- Carroll County, OH R+55
- King George County, VA R+23
- Gillespie County, TX R+56
- Yazoo County, MS D+17
- Wasco County, OR R+14
- Marlboro County, SC D+9
- Geneva County, AL R+74
- Oceana County, MI R+28
- Stephens County, GA R+53
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.