Iselin, NJ Political Map | Democrat & Republican Areas in Iselin

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

Iselin is a true toss-up. About 51% of voters here vote Democratic and 49% Republican.

 

About 61% of adults in Iselin typically vote, near the U.S. average of about 62%. Among adults in Iselin, ~31% vote Democratic, ~30% Republican, and ~39% don't vote. The map below shows estimated turnout by block group.

How Iselin compares

Among cities within 25 miles, Iselin sits roughly in the middle of the political spectrum, with 111 neighbors leaning further in the place's direction and 129 leaning the other way.

Politically, Iselin sits close to the rest of New Jersey.

Politics vary noticeably by neighborhood within Iselin. The south side runs the most Democratic (D+19) and the west side runs the most Republican (R+10), a spread of about 29 points.

Why Iselin leans the way it does

Density, race composition, education, and family structure all sit close to their national averages in Iselin. The lean here lands roughly where demographic data alone would predict.

Paved land cover and Democratic lean

Places with extensive paved surfaces tend to lean Democratic; Iselin, NJ sits in the top tenth nationally on this measure. Paved ground does not change how people vote; it mostly reflects how urban and built-up a place is.

Why turnout in Iselin looks the way it does

Crowded housing lines up with lower turnout. About 7% of homes in Iselin have more than one occupant per room, above 92% of cities. Strong routine healthcare access lines up with higher turnout, and Iselin sits in the top quarter on routine-care measures. Renters vote less often than owners, and about 32% of households in Iselin rent, above 87% of cities. 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.