Port Jefferson, NY Political Map | Democrat & Republican Areas in Port Jefferson

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

Port Jefferson leans slightly Democratic by roughly 12 points: about 56% of voters vote Democratic and 44% Republican.

 

About 76% of adults in Port Jefferson typically vote, above the U.S. average of about 62%. Among adults in Port Jefferson, ~43% vote Democratic, ~34% Republican, and ~23% don't vote. The map below shows estimated turnout by block group.

How Port Jefferson compares

Among cities within 25 miles, Port Jefferson leans more Democratic than 103 of 112 neighbors.

Politically, Port Jefferson sits close to the rest of New York.

Politics vary noticeably by neighborhood within Port Jefferson. The south side runs the most Democratic (D+22) and the northeast side runs the most Republican (Even), a spread of about 24 points.

Why Port Jefferson leans the way it does

This analysis examined 14,881 data points per city to find what predicts political lean and turnout. The items below are a few correlations that stood out for Port Jefferson, not a ranked or complete list of what matters most.

Areas with high college attainment vote Democratic. About 67% of adults in Port Jefferson hold a bachelor's degree, about 39 points above the U.S. average of 28%. Dense areas vote Democratic, and Port Jefferson sits in the top fifth on density (about 91%, above 97% of cities). A high never-married share predicts Democratic voting, and about 33% of adults in Port Jefferson have never been married, above 84% of cities.

Walkability and Democratic lean

Places with a highly walkable street grid tend to lean Democratic; Port Jefferson, NY sits in the top tenth nationally on this measure. A walkable street grid does not change how people vote; it mostly reflects how urban a place is.

Why turnout in Port Jefferson looks the way it does

Areas with strong routine healthcare access turn out at higher rates. Port Jefferson 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 74%, about 14 points above the U.S. average of 60%. High high-school completion lines up with higher turnout, and about 97% of adults in Port Jefferson have completed high school, above 92% 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 York State Board 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.