South New Castle leans Republican by roughly 30 points: about 35% of voters vote Democratic and 65% Republican.
About 69% of adults in South New Castle typically vote, above the U.S. average of about 62%. Among adults in South New Castle, ~24% vote Democratic, ~45% Republican, and ~31% don't vote. The map below shows estimated turnout by block group.
How South New Castle compares
Among cities within 25 miles, South New Castle leans more Republican than 47 of 134 neighbors.
South New Castle runs about 28 points more Republican than Pennsylvania as a whole.
Why South New Castle 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 South New Castle, not a ranked or complete list of what matters most.
South New Castle votes Republican even though it is densely developed (about 84%, far above the Pennsylvania average of 33%). State and regional patterns outweigh the Democratic lean that density usually predicts here. A high family-household share predicts Republican voting, and about 75% of households in South New Castle are family households, above 77% of cities.
Population density and Democratic lean
Places with high population density tend to lean Democratic; South New Castle, PA sits in the top tenth nationally on this measure.
Why turnout in South New Castle looks the way it does
Turnout in South New Castle sits close to the national pattern. Learn more about the findings and methodology on the political spectrum map.
Nearby Cities
- New Castle, PA R+21
- West Pittsburg, PA R+43
- North Edinburg, PA R+35
- Wampum, PA R+47
- Princeton, PA R+51
- Energy, PA R+50
- New Beaver, PA R+51
- Edinburg, PA R+45
- Neshannock Falls, PA R+51
- Bessemer, PA R+49
Cities with Similar Populations
- Kelford, NC D+51
- Irvine, PA R+48
- Oliver Beach, MD R+44
- Lazbuddie, TX R+82
- Mason Cove, VA R+49
- Lakemont, SC R+65
- Luck, NC R+35
- Clayville, RI R+18
- Sideview, KY R+61
- Mount Harmony, WV R+46
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.