53403 leans heavily Democratic by roughly 36 points: about 68% of voters vote Democratic and 32% Republican.
About 67% of adults in 53403 typically vote, near the U.S. average of about 62%. Among adults in 53403, ~46% vote Democratic, ~21% Republican, and ~33% don't vote. The map below shows estimated turnout by block group.
How 53403 compares
Among zip codes within 15 miles, 53403 leans more Democratic than 14 of 15 neighbors.
53403 runs about 37 points more Democratic than Wisconsin as a whole. Wisconsin is roughly evenly split, and 53403 sits clearly on the Democratic side.
Politics vary noticeably by block within 53403. The north side is the most Democratic-leaning (D+66) and the southwest side is the least Democratic-leaning (D+14), a spread of about 52 points.
Why 53403 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 53403, not a ranked or complete list of what matters most.
Dense areas vote Democratic. About 84% of residents in 53403 live in densely developed areas, about 48 points above the U.S. average of 36%. A high never-married share predicts Democratic voting, and about 43% of adults in 53403 have never been married, above 90% of zip codes. 53403 runs against the grain of Wisconsin, a Democratic-leaning outlier in a roughly evenly split state.
Population density and Democratic lean
Places with high population density tend to lean Democratic; 53403, WI sits in the top tenth nationally on this measure.
Why turnout in 53403 looks the way it does
Areas with limited routine healthcare access turn out at lower rates. 53403 is in the bottom quarter nationally for routine-care measures such as insurance coverage, preventive screenings, and dental visits. 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.