15234 leans slightly Democratic by roughly 10 points: about 55% of voters vote Democratic and 45% Republican.
About 84% of adults in 15234 typically vote, above the U.S. average of about 62%. Among adults in 15234, ~46% vote Democratic, ~38% Republican, and ~16% don't vote. The map below shows estimated turnout by block group.
How 15234 compares
Among zip codes within 15 miles, 15234 leans more Democratic than 55 of 98 neighbors.
15234 runs about 12 points more Democratic than Pennsylvania as a whole. Pennsylvania is roughly evenly split, and 15234 sits clearly on the Democratic side.
Politics vary noticeably by block within 15234. The northwest side runs the most Democratic (D+38) and the northeast side runs the most Republican (R+3), a spread of about 41 points.
Why 15234 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 15234, not a ranked or complete list of what matters most.
Dense areas vote Democratic. About 98% of residents in 15234 live in densely developed areas, about 62 points above the U.S. average of 36%. High college attainment predicts Democratic voting, and 15234 sits in the top quarter (about 43%, above 83% of zip codes). A high never-married share predicts Democratic voting, and about 35% of adults in 15234 have never been married, above 80% of zip codes.
Population density and Democratic lean
Places with high population density tend to lean Democratic; 15234, PA sits in the top tenth nationally on this measure.
Why turnout in 15234 looks the way it does
Areas with high high-school completion turn out at higher rates. About 97% of adults in 15234 have completed high school, about 6 points above the Pennsylvania average of 91%. 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.