Buchanan County leans heavily Republican by roughly 36 points: about 32% of voters vote Democratic and 68% Republican.
About 91% of adults in Buchanan County typically vote, above the U.S. average of about 62%. Among adults in Buchanan County, ~29% vote Democratic, ~62% Republican, and ~9% don't vote. The map below shows estimated turnout by block group.
How Buchanan County compares
Among counties within 50 miles, Buchanan County leans more Republican than 7 of 12 neighbors.
Buchanan County runs about 22 points more Republican than Iowa as a whole.
Politics vary noticeably by city within Buchanan County. The northwest side is the most Republican-leaning (R+45) and the west side is the least Republican-leaning (R+32), a spread of about 13 points.
Why Buchanan County leans the way it does
Density, race composition, education, and family structure all sit close to their national averages in Buchanan 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; Buchanan 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 Buchanan County looks the way it does
Areas with strong routine healthcare access turn out at higher rates. Buchanan 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%. Homeowners vote more often than renters, and about 82% of households in Buchanan County own their home, above 89% of counties. High high-school completion lines up with higher turnout, and about 94% of adults in Buchanan County have completed high school, above 83% of counties. Learn more about the findings and methodology on the political spectrum map.
Nearby Counties
- Fayette County, IA R+30
- Black Hawk County, IA D+3
- Delaware County, IA R+39
- Benton County, IA R+36
- Bremer County, IA R+25
- Linn County, IA D+7
- Clayton County, IA R+39
- Jones County, IA R+27
- Grundy County, IA R+42
- Tama County, IA R+25
Counties with Similar Populations
- Kewaunee County, WI R+39
- Colorado County, TX R+42
- Greene County, VA R+26
- Allen County, KY R+64
- Barnwell County, SC R+13
- Dukes County, MA D+41
- Meriwether County, GA R+22
- Adams County, WA R+31
- Hutchinson County, TX R+60
- Jones County, IA R+27
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.