54121 leans heavily Republican by roughly 36 points: about 32% of voters vote Democratic and 68% Republican.
About 83% of adults in 54121 typically vote, above the U.S. average of about 62%. Among adults in 54121, ~27% vote Democratic, ~56% Republican, and ~17% don't vote. The map below shows estimated turnout by block group.
How 54121 compares
Among zip codes within 15 miles, 54121 leans more Republican than 4 of 6 neighbors.
54121 runs about 35 points more Republican than Wisconsin as a whole.
Politics vary noticeably by block within 54121. The southwest side is the most Republican-leaning (R+53) and the east side is the least Republican-leaning (R+19), a spread of about 34 points.
Why 54121 leans the way it does
This analysis examined 14,881 data points per zip code to find what predicts political lean and turnout. The items below are a few correlations that stood out for 54121, not a ranked or complete list of what matters most.
Rural areas with a high white share vote Republican. 54121 sits in the bottom quarter on density and about 94% of residents are non-Hispanic white, about 8 points above the Wisconsin average of 87%.
Cancer-screening access and voter turnout
Places with high colon-cancer-screening access tend to turn out at a higher rate; 54121, WI sits in the top tenth nationally on this measure. Cancer screening does not drive turnout; it reflects income, insurance, and healthcare access.
Why turnout in 54121 looks the way it does
Areas with strong routine healthcare access turn out at higher rates. 54121 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 66%, about 6 points above the U.S. average of 60%. Homeowners vote more often than renters, and about 90% of households in 54121 own their home, above 86% of zip codes. Learn more about the findings and methodology on the political spectrum map.
Nearby Zip Codes
Zip Codes with Similar Populations
Sources and methodology
Precinct-level voting records used to fit the model come from Wisconsin Elections Commission, 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.