Montgomery County leans Democratic by roughly 22 points: about 61% of voters vote Democratic and 39% Republican.
About 86% of adults in Montgomery County typically vote, above the U.S. average of about 62%. Among adults in Montgomery County, ~52% vote Democratic, ~34% Republican, and ~14% don't vote. The map below shows estimated turnout by block group.
How Montgomery County compares
Among counties within 50 miles, Montgomery County leans more Democratic than 11 of 16 neighbors.
Montgomery County runs about 23 points more Democratic than Pennsylvania as a whole. Pennsylvania is roughly evenly split, and Montgomery County sits clearly on the Democratic side.
Politics vary noticeably by city within Montgomery County. The southeast side runs the most Democratic (D+45) and the northwest side runs the most Republican (R+3), a spread of about 48 points.
Why Montgomery 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 Montgomery County, not a ranked or complete list of what matters most.
Areas with high college attainment vote Democratic. About 53% of adults in Montgomery County hold a bachelor's degree, about 25 points above the U.S. average of 28%. Dense areas vote Democratic, and Montgomery County sits in the top fifth on density (about 84%, above 97% of counties). Montgomery County runs against the grain of Pennsylvania, a Democratic-leaning outlier in a roughly evenly split state.
Preventive-care access and voter turnout
Places with strong routine preventive-care access tend to turn out at a higher rate; Montgomery County, PA sits in the top tenth nationally on this measure. Dental visits do not drive turnout; the rate reflects income, insurance, and healthcare access, which line up with who votes.
Why turnout in Montgomery County looks the way it does
Areas with strong routine healthcare access turn out at higher rates. Montgomery County 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 71%, about 11 points above the U.S. average of 60%. High high-school completion lines up with higher turnout, and about 95% of adults in Montgomery County have completed high school, above 92% of counties. Learn more about the findings and methodology on the political spectrum map.
Nearby Counties
- Philadelphia County, PA D+56
- Bucks County, PA Even
- Delaware County, PA D+27
- Chester County, PA D+14
- Camden County, NJ D+30
- Burlington County, NJ D+16
- Gloucester County, NJ R+2
- Lehigh County, PA D+6
- Mercer County, NJ D+38
- Berks County, PA R+8
Counties with Similar Populations
- Baltimore County, MD D+28
- Worcester County, MA D+12
- Middlesex County, NJ D+11
- Essex County, NJ D+48
- El Paso County, TX D+15
- Ventura County, CA D+16
- Hidalgo County, TX R+2
- San Francisco County, CA D+61
- Macomb County, MI R+10
- Hamilton County, OH D+21
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.