Jefferson County, KS Political Map | Democrat & Republican Areas in Jefferson County

By the BestNeighborhood data science team. Last updated May 2026.

Jefferson County leans heavily Republican by roughly 50 points: about 25% of voters vote Democratic and 75% Republican.

 

About 75% of adults in Jefferson County typically vote, above the U.S. average of about 62%. Among adults in Jefferson County, ~19% vote Democratic, ~56% Republican, and ~25% don't vote. The map below shows estimated turnout by block group.

How Jefferson County compares

Among counties within 50 miles, Jefferson County leans more Republican than 13 of 15 neighbors.

Jefferson County runs about 33 points more Republican than Kansas as a whole.

Politics vary noticeably by city within Jefferson County. The northeast side is the most Republican-leaning (R+54) and the northwest side is the least Republican-leaning (R+43), a spread of about 12 points.

Why Jefferson 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 Jefferson County, not a ranked or complete list of what matters most.

Rural areas with a high white share vote Republican. Jefferson County sits in the bottom quarter on density and about 91% of residents are non-Hispanic white, about 6 points above the Kansas average of 85%. A high family-household share predicts Republican voting, and about 70% of households in Jefferson County are family households, above 82% of counties.

Paved land cover and Republican lean

Places with little paved surface tend to lean Republican; Jefferson County, KS sits in the bottom quarter nationally on this measure. Paved ground does not change how people vote; it mostly reflects how urban and built-up a place is.

Why turnout in Jefferson County looks the way it does

Areas with strong routine healthcare access turn out at higher rates. Jefferson 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 67%, about 7 points above the U.S. average of 60%. Homeowners vote more often than renters, and about 87% of households in Jefferson County own their home, compared to around 71% in nearby counties. High high-school completion lines up with higher turnout, and about 94% of adults in Jefferson County have completed high school, above 88% of counties. Learn more about the findings and methodology on the political spectrum map.

Sources and methodology

Precinct-level voting records used to fit the model come from Kansas 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.