New Castle leans heavily Republican by roughly 40 points: about 30% of voters vote Democratic and 70% Republican.
About 58% of adults in New Castle typically vote, near the U.S. average of about 62%. Among adults in New Castle, ~17% vote Democratic, ~40% Republican, and ~43% 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 Republican than 8 of 88 neighbors.
New Castle runs about 21 points more Republican than Indiana as a whole.
Politics vary noticeably by neighborhood within New Castle. The northeast side is the most Republican-leaning (R+51) and the north side is the least Republican-leaning (R+25), a spread of about 26 points.
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.
New Castle votes Republican even though it is densely developed (about 62%, far above the Indiana average of 25%). State and regional patterns outweigh the Democratic lean that density usually predicts here. Low college attainment predicts Republican voting, and New Castle sits in the bottom quarter (about 14%, below 81% of cities).
High-school completion, developed land, and voter turnout
Places that combine low high-school-completion share and a heavily developed built environment tend to turn out at a lower rate, as New Castle, IN does.
Why turnout in New Castle looks the way it does
Renters vote less often than owners. About 31% of households in New Castle rent, about 6 points above the U.S. average of 25%. Learn more about the findings and methodology on the political spectrum map.
Nearby Cities
- Westwood, IN R+52
- Mount Summit, IN R+56
- New Lisbon, IN R+56
- Messick, IN R+58
- Greensboro, IN R+59
- Millville, IN R+61
- Sulphur Springs, IN R+57
- Cadiz, IN R+58
- Spiceland, IN R+59
- Lewisville, IN R+62
Cities with Similar Populations
- Flushing, MI R+5
- Ferndale, WA Even
- Rochester, MI Even
- Chevy Chase, MD D+69
- Mountain Home, AR R+47
- Mira Loma, CA Even
- El Cerrito, CA D+70
- Mount Holly, NC R+21
- Gallup, NM D+12
- Holbrook, NY R+26
All Local Stats
Home Services
Sources and methodology
Precinct-level voting records used to fit the model come from Indiana Secretary of State, 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.