15901 leans slightly Democratic by roughly 12 points: about 56% of voters vote Democratic and 44% Republican.
About 53% of adults in 15901 typically vote, below the U.S. average of about 62%. Among adults in 15901, ~29% vote Democratic, ~23% Republican, and ~48% don't vote. The map below shows estimated turnout by block group.
How 15901 compares
Among zip codes within 15 miles, 15901 is the most Democratic-leaning.
15901 runs about 14 points more Democratic than Pennsylvania as a whole. Pennsylvania is roughly evenly split, and 15901 sits clearly on the Democratic side.
Politics vary noticeably by block within 15901. The south side is the most Democratic-leaning (D+20) and the northeast side is the least Democratic-leaning (D+6), a spread of about 14 points.
Why 15901 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 15901, not a ranked or complete list of what matters most.
Dense areas vote Democratic. About 83% of residents in 15901 live in densely developed areas, about 47 points above the U.S. average of 36%. A high never-married share predicts Democratic voting, and about 46% of adults in 15901 have never been married, above 93% of zip codes. 15901 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; 15901, PA sits in the top tenth 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 15901 looks the way it does
Areas with limited routine healthcare access turn out at lower rates. 15901 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 15 points below the Pennsylvania average of 64%. Renters vote less often than owners, and about 58% of households in 15901 rent, compared to around 20% in nearby zip codes. High-crime urban areas turn out at lower rates, and 15901 sits in the top 15% on a violent-crime measure. 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.