Mendham is a true toss-up. About 50% of voters here vote Democratic and 50% Republican.
About 93% of adults in Mendham typically vote, above the U.S. average of about 62%. Among adults in Mendham, ~46% vote Democratic, ~47% Republican, and ~7% don't vote. The map below shows estimated turnout by block group.
How Mendham compares
Among cities within 25 miles, Mendham sits roughly in the middle of the political spectrum, with 131 neighbors leaning further in the place's direction and 99 leaning the other way.
Mendham runs about 6 points more Republican than New Jersey as a whole.
Why Mendham leans the way it does
Density, race composition, education, and family structure all sit close to their national averages in Mendham. The lean here lands roughly where demographic data alone would predict.
Population density and Democratic lean
Places with high population density tend to lean Democratic; Mendham, NJ sits in the top quarter nationally on this measure.
Why turnout in Mendham looks the way it does
Areas with strong routine healthcare access turn out at higher rates. Mendham 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 80%, about 20 points above the U.S. average of 60%. High high-school completion lines up with higher turnout, and about 98% of adults in Mendham have completed high school, above 95% of cities. Learn more about the findings and methodology on the political spectrum map.
Nearby Cities
- Brookside, NJ R+3
- Chester, NJ R+7
- Randolph, NJ D+7
- Bernardsville, NJ Even
- Succasunna, NJ R+16
- Peapack and Gladstone, NJ Even
- Far Hills, NJ R+5
- Madisonville, NJ Even
- Morristown, NJ D+23
- Mine Hill, NJ R+3
Cities with Similar Populations
- Inwood, NY D+14
- Lebanon, NH D+45
- Strawberry Plains, TN R+65
- Greenwell Springs, LA R+56
- Vale, NC R+61
- Talbott, TN R+62
- Oak Brook, IL Even
- New Boston, MI R+27
- Prairie Grove, AR R+46
- Oroville East, CA R+29
All Local Stats
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Sources and methodology
Precinct-level voting records used to fit the model come from New Jersey Division 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.