Monmouth County, NJ Political Map | Democrat & Republican Areas in Monmouth County

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

Monmouth County leans slightly Republican by roughly 8 points: about 46% of voters vote Democratic and 54% Republican.

 

About 81% of adults in Monmouth County typically vote, above the U.S. average of about 62%. Among adults in Monmouth County, ~37% vote Democratic, ~44% Republican, and ~19% don't vote. The map below shows estimated turnout by block group.

How Monmouth County compares

Among counties within 50 miles, Monmouth County leans more Republican than 17 of 19 neighbors.

Monmouth County runs about 14 points more Republican than New Jersey as a whole. New Jersey leans Democratic overall, while Monmouth County is one of the few Republican-leaning pockets.

Politics vary noticeably by city within Monmouth County. The southeast side runs the most Democratic (D+19) and the southwest side runs the most Republican (R+23), a spread of about 42 points.

Why Monmouth 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 Monmouth County, not a ranked or complete list of what matters most.

Monmouth County votes Republican even though it is densely developed (about 75%, modestly above the New Jersey average of 61%). State and regional patterns outweigh the Democratic lean that density usually predicts here. A high family-household share predicts Republican voting, and about 71% of households in Monmouth County are family households, above 84% of counties. Monmouth County runs against the grain of New Jersey, a Republican-leaning pocket in a Democratic-leaning state.

Cancer-screening access and voter turnout

Places with high colon-cancer-screening access tend to turn out at a higher rate; Monmouth County, NJ sits in the top quarter nationally on this measure. Cancer screening does not drive turnout; it reflects income, insurance, and healthcare access.

Why turnout in Monmouth County looks the way it does

Areas with strong routine healthcare access turn out at higher rates. Monmouth 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 94% of adults in Monmouth County have completed high school, above 86% of counties. 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 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.