16421 leans Republican by roughly 20 points: about 40% of voters vote Democratic and 60% Republican.
About 89% of adults in 16421 typically vote, above the U.S. average of about 62%. Among adults in 16421, ~35% vote Democratic, ~53% Republican, and ~12% don't vote. The map below shows estimated turnout by block group.
How 16421 compares
Among zip codes within 15 miles, 16421 leans more Republican than 13 of 18 neighbors.
16421 runs about 17 points more Republican than Pennsylvania as a whole.
Politics vary noticeably by block within 16421. The east side is the most Republican-leaning (R+28) and the west side is the least Republican-leaning (R+14), a spread of about 14 points.
Why 16421 leans the way it does
Density, race composition, education, and family structure all sit close to their national averages in 16421. The lean here lands roughly where demographic data alone would predict.
High-school completion and voter turnout
Places with high-school-completion-heavy adults tend to turn out at a higher rate; 16421, PA sits in the top quarter nationally on this measure.
Why turnout in 16421 looks the way it does
Areas with strong routine healthcare access turn out at higher rates. 16421 is in the top quarter nationally for routine-care measures such as insurance coverage, preventive screenings, and dental visits. The dental-visit rate here is about 67%, about 7 points above the U.S. average of 60%. High high-school completion lines up with higher turnout, and about 96% of adults in 16421 have completed high school, above 84% of zip codes. 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.