15120 leans Democratic by roughly 24 points: about 62% of voters vote Democratic and 38% Republican.
About 71% of adults in 15120 typically vote, above the U.S. average of about 62%. Among adults in 15120, ~44% vote Democratic, ~27% Republican, and ~29% don't vote. The map below shows estimated turnout by block group.
How 15120 compares
Among zip codes within 15 miles, 15120 leans more Democratic than 73 of 103 neighbors.
15120 runs about 26 points more Democratic than Pennsylvania as a whole. Pennsylvania is roughly evenly split, and 15120 sits clearly on the Democratic side.
Politics vary noticeably by block within 15120. The north side is the most Democratic-leaning (D+58) and the southeast side is the least Democratic-leaning (D+7), a spread of about 51 points.
Why 15120 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 15120, not a ranked or complete list of what matters most.
Dense areas vote Democratic. About 91% of residents in 15120 live in densely developed areas, about 54 points above the U.S. average of 36%. A high never-married share predicts Democratic voting, and about 43% of adults in 15120 have never been married, above 90% of zip codes. 15120 runs against the grain of Pennsylvania, a Democratic-leaning outlier in a roughly evenly split state.
Paved land cover and Democratic lean
Places with extensive paved surfaces tend to lean Democratic; 15120, PA sits in the top 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 15120 looks the way it does
Turnout in 15120 sits close to the national pattern. Routine healthcare access, homeownership, education, and food security all land near their national averages here. 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 Pennsylvania Department of State, Bureau of 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.