New Castle leans heavily Democratic by roughly 40 points: about 70% of voters vote Democratic and 30% Republican. These figures are model estimates: New Hampshire did not have precinct-level voting records available for training, so the numbers above come from demographic and health features rather than local ground truth.
About 91% of adults in New Castle typically vote, above the U.S. average of about 62%. Among adults in New Castle, ~64% vote Democratic, ~27% Republican, and ~9% don't vote. The map below shows estimated turnout by block group.
How New Castle compares
Among cities within 25 miles, New Castle leans more Democratic than 68 of 69 neighbors.
New Castle runs about 37 points more Democratic than New Hampshire as a whole.
Why New Castle 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 New Castle, not a ranked or complete list of what matters most.
Areas with high college attainment vote Democratic. About 69% of adults in New Castle hold a bachelor's degree, about 40 points above the U.S. average of 28%.
Population density, never-married share, and Democratic lean
Places that combine high population density and a low never-married share tend to lean Democratic, as New Castle, NH does.
Why turnout in New Castle looks the way it does
Areas with strong routine healthcare access turn out at higher rates. New Castle 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 77%, about 17 points above the U.S. average of 60%. Homeowners vote more often than renters, and about 93% of households in New Castle own their home, about 18 points above the U.S. average of 75%. Learn more about the findings and methodology on the political spectrum map.
Nearby Cities
- Kittery, ME D+26
- Kittery Point, ME D+27
- Portsmouth, NH D+39
- Rye, NH D+18
- Eliot, ME Even
- York, ME D+15
- West Rye, NH D+10
- Rye Beach, NH D+15
- Greenland, NH D+16
- Newington, NH D+21
Cities with Similar Populations
- Smith Lake, NM D+24
- Brimhall, NM D+44
- Loraine, TX R+72
- Four Lakes, WA R+31
- Pechin, PA R+54
- Plum Branch, SC D+10
- East Carbon, UT R+68
- Sipsey, AL R+72
- Ripley, OK R+60
- Cornell, IL R+55
Sources and methodology
Precinct-level voting records used to fit the model come from New Hampshire Secretary of State, Elections Division, 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. NH did not have precinct-level voting records available for training, so the figures here come from extrapolation across demographic, health, and land-use features rather than local ground truth. Full methodology and findings: political spectrum map.
Methodology reviewed by the BestNeighborhood data team. Last updated May 2026.