51105 is a true toss-up. About 52% of voters here vote Democratic and 48% Republican.
About 44% of adults in 51105 typically vote, below the U.S. average of about 62%. Among adults in 51105, ~23% vote Democratic, ~21% Republican, and ~56% don't vote. The map below shows estimated turnout by block group.
How 51105 compares
Among zip codes within 15 miles, 51105 leans more Democratic than 16 of 19 neighbors.
51105 runs about 17 points more Democratic than Iowa as a whole. Iowa leans Republican overall, while 51105 is one of the few Democratic-leaning pockets.
Politics vary noticeably by block within 51105. The west side runs the most Democratic (D+30) and the northeast side runs the most Republican (R+27), a spread of about 57 points.
Why 51105 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 51105, not a ranked or complete list of what matters most.
51105 votes against the grain of Iowa. Iowa leans Republican overall, while 51105 runs about 17 points more Democratic.
Population density and Democratic lean
Places with high population density tend to lean Democratic; 51105, IA sits in the top tenth nationally on this measure.
Why turnout in 51105 looks the way it does
Areas with limited routine healthcare access turn out at lower rates. 51105 is in the bottom quarter nationally for routine-care measures such as insurance coverage, preventive screenings, and dental visits. The dental-visit rate here is about 48%, about 20 points below the Iowa average of 68%. Renters vote less often than owners, and about 48% of households in 51105 rent, about 23 points above the U.S. average of 25%. High food insecurity lines up with lower turnout, and about 31% of adults in 51105 report food insecurity, above 94% 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 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.