15131 leans slightly Republican by roughly 8 points: about 46% of voters vote Democratic and 54% Republican.
About 84% of adults in 15131 typically vote, above the U.S. average of about 62%. Among adults in 15131, ~38% vote Democratic, ~45% Republican, and ~17% don't vote. The map below shows estimated turnout by block group.
How 15131 compares
Among zip codes within 15 miles, 15131 leans more Republican than 52 of 105 neighbors.
15131 runs about 7 points more Republican than Pennsylvania as a whole.
Politics vary noticeably by block within 15131. The southeast side is the most split-leaning (R+25) and the west side is the least split-leaning (Even), a spread of about 25 points.
Why 15131 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 15131, not a ranked or complete list of what matters most.
15131 votes Republican even though it is densely developed (about 69%, far above the Pennsylvania average of 33%). Here an older population outweighs the Democratic lean that density usually predicts.
Cancer-screening access and voter turnout
Places with high colon-cancer-screening access tend to turn out at a higher rate; 15131, PA sits above the national average on this measure. Cancer screening does not drive turnout; it reflects income, insurance, and healthcare access.
Why turnout in 15131 looks the way it does
Areas with high high-school completion turn out at higher rates. About 96% of adults in 15131 have completed high school, about 7 points above the U.S. average of 90%. 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.