Upper Darby, PA Political Map | Democrat & Republican Areas in Upper Darby

By the BestNeighborhood data science team. Last updated May 2026.

Upper Darby is a Democratic stronghold. About 76% of voters here vote Democratic and 24% Republican.

 

About 59% of adults in Upper Darby typically vote, near the U.S. average of about 62%. Among adults in Upper Darby, ~45% vote Democratic, ~14% Republican, and ~41% don't vote. The map below shows estimated turnout by block group.

How Upper Darby compares

Among cities within 25 miles, Upper Darby leans more Democratic than 235 of 253 neighbors.

Upper Darby runs about 54 points more Democratic than Pennsylvania as a whole. Pennsylvania is roughly evenly split, and Upper Darby sits clearly on the Democratic side.

Politics vary noticeably by neighborhood within Upper Darby. The southeast side is the most Democratic-leaning (D+67) and the east side is the least Democratic-leaning (D+35), a spread of about 32 points.

Why Upper Darby leans the way it does

This analysis examined 14,881 data points per city to find what predicts political lean and turnout. The items below are a few correlations that stood out for Upper Darby, not a ranked or complete list of what matters most.

Dense areas vote Democratic. About 99% of residents in Upper Darby live in densely developed areas, about 63 points above the U.S. average of 36%. A high never-married share predicts Democratic voting, and about 48% of adults in Upper Darby have never been married, above 97% of cities. Upper Darby runs against the grain of Pennsylvania, a Democratic-leaning outlier in a roughly evenly split state.

Population density and Democratic lean

Places with high population density tend to lean Democratic; Upper Darby, PA sits in the top tenth nationally on this measure.

Why turnout in Upper Darby looks the way it does

Renters vote less often than owners. About 46% of households in Upper Darby rent, about 21 points above the U.S. average of 25%. Low high-school completion lines up with lower turnout, and about 86% of adults in Upper Darby have completed high school, below 75% of cities. Learn more about the findings and methodology on the political spectrum map.

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.