Dauphin County leans slightly Democratic by roughly 12 points: about 56% of voters vote Democratic and 44% Republican.
About 74% of adults in Dauphin County typically vote, above the U.S. average of about 62%. Among adults in Dauphin County, ~41% vote Democratic, ~33% Republican, and ~26% don't vote. The map below shows estimated turnout by block group.
How Dauphin County compares
Among counties within 50 miles, Dauphin County is the most Democratic-leaning.
Dauphin County runs about 14 points more Democratic than Pennsylvania as a whole. Pennsylvania is roughly evenly split, and Dauphin County sits clearly on the Democratic side.
Politics vary noticeably by city within Dauphin County. The west side runs the most Democratic (D+64) and the northeast side runs the most Republican (R+25), a spread of about 89 points.
Why Dauphin 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 Dauphin County, not a ranked or complete list of what matters most.
Dense areas vote Democratic. About 69% of residents in Dauphin County live in densely developed areas, about 32 points above the U.S. average of 36%. High college attainment predicts Democratic voting, and Dauphin County sits in the top quarter (about 34%, above 84% of counties). A high never-married share predicts Democratic voting, and about 34% of adults in Dauphin County have never been married, above 80% of counties.
Population density and Democratic lean
Places with high population density tend to lean Democratic; Dauphin County, PA sits in the top tenth nationally on this measure.
Why turnout in Dauphin County looks the way it does
Turnout in Dauphin 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
- Cumberland County, PA R+9
- Lebanon County, PA R+31
- Perry County, PA R+52
- York County, PA R+21
- Lancaster County, PA R+17
- Juniata County, PA R+62
- Snyder County, PA R+50
- Adams County, PA R+35
- Northumberland County, PA R+39
- Schuylkill County, PA R+36
Counties with Similar Populations
- Winnebago County, IL D+7
- Ingham County, MI D+31
- Benton County, AR R+26
- San Luis Obispo County, CA D+8
- York County, SC R+17
- Anchorage Municipality, AK D+20
- Merced County, CA R+3
- Leon County, FL D+26
- Lexington County, SC R+30
- Alachua County, FL D+22
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.