Philadelphia County is a Democratic stronghold. About 78% of voters here vote Democratic and 22% Republican.
About 69% of adults in Philadelphia County typically vote, above the U.S. average of about 62%. Among adults in Philadelphia County, ~54% vote Democratic, ~15% Republican, and ~31% don't vote. The map below shows estimated turnout by block group.
How Philadelphia County compares
Among counties within 50 miles, Philadelphia County is the most Democratic-leaning.
Philadelphia County runs about 58 points more Democratic than Pennsylvania as a whole. Pennsylvania is roughly evenly split, and Philadelphia County sits clearly on the Democratic side.
Politics vary noticeably by city within Philadelphia County. The north side is the most Democratic-leaning (D+87) and the northeast side is the least Democratic-leaning (D+20), a spread of about 67 points.
Why Philadelphia County leans the way it does
This analysis examined 14,881 data points per county to find what predicts political lean and turnout. The items below are a few correlations that stood out for Philadelphia County, not a ranked or complete list of what matters most.
Dense areas vote Democratic. About 98% of residents in Philadelphia County live in densely developed areas, about 62 points above the U.S. average of 36%. High college attainment predicts Democratic voting, and Philadelphia County sits in the top quarter (about 34%, above 85% of counties). Philadelphia County runs against the grain of Pennsylvania, a Democratic-leaning outlier in a roughly evenly split state.
Walkability and Democratic lean
Places with a highly walkable street grid tend to lean Democratic; Philadelphia County, PA sits in the top tenth nationally on this measure. A walkable street grid does not change how people vote; it mostly reflects how urban a place is.
Why turnout in Philadelphia County looks the way it does
Turnout in Philadelphia County 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 Counties
- Camden County, NJ D+30
- Delaware County, PA D+27
- Montgomery County, PA D+21
- Burlington County, NJ D+16
- Bucks County, PA Even
- Gloucester County, NJ R+2
- Chester County, PA D+14
- Salem County, NJ R+12
- Mercer County, NJ D+38
- New Castle County, DE D+33
Counties with Similar Populations
- Sacramento County, CA D+20
- Middlesex County, MA D+37
- Alameda County, CA D+49
- New York County, NY D+62
- Palm Beach County, FL D+5
- Bronx County, NY D+43
- Hillsborough County, FL Even
- Suffolk County, NY R+8
- Orange County, FL D+14
- Wayne County, MI D+33
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.