17921 leans heavily Republican by roughly 30 points: about 35% of voters vote Democratic and 65% Republican.
About 68% of adults in 17921 typically vote, above the U.S. average of about 62%. Among adults in 17921, ~24% vote Democratic, ~44% Republican, and ~32% don't vote. The map below shows estimated turnout by block group.
How 17921 compares
Among zip codes within 15 miles, 17921 leans more Republican than 7 of 44 neighbors.
17921 runs about 29 points more Republican than Pennsylvania as a whole.
Politics vary noticeably by block within 17921. The south side runs the most Democratic (D+26) and the southwest side runs the most Republican (R+54), a spread of about 80 points.
Why 17921 leans the way it does
Density, race composition, education, and family structure all sit close to their national averages in 17921. The lean here lands roughly where demographic data alone would predict.
Population density and Democratic lean
Places with high population density tend to lean Democratic; 17921, PA sits above the national average on this measure.
Why turnout in 17921 looks the way it does
Turnout in 17921 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.