Petroleum is a Republican stronghold. About 15% of voters here vote Democratic and 85% Republican.
About 71% of adults in Petroleum typically vote, above the U.S. average of about 62%. Among adults in Petroleum, ~11% vote Democratic, ~60% Republican, and ~29% don't vote. The map below shows estimated turnout by block group.
How Petroleum compares
Among cities within 25 miles, Petroleum leans more Republican than 68 of 85 neighbors.
Petroleum runs about 50 points more Republican than Indiana as a whole.
Why Petroleum 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 Petroleum, not a ranked or complete list of what matters most.
Areas with a high white share and below-average college attainment vote Republican. In Petroleum, more than 99% of residents are non-Hispanic white, about 27 points above the U.S. average of 72%; about 11% of adults hold a bachelor's degree, about 11 points below the Indiana average of 22%. Car-dependent areas vote Republican, and about 92% of residents in Petroleum drive to work alone, above 96% of cities. A high family-household share predicts Republican voting, and about 82% of households in Petroleum are family households, above 92% of cities.
Population density and Republican lean
Places with low population density tend to lean Republican; Petroleum, IN sits below the national average on this measure.
Why turnout in Petroleum looks the way it does
Turnout in Petroleum sits close to the national pattern. Routine healthcare access, homeownership, education, and food security all land near their national averages here. Learn more about the findings and methodology on the political spectrum map.
Nearby Cities
- Keystone, IN R+68
- Reiffsburg, IN R+69
- Domestic, IN R+69
- Fiat, IN R+66
- Poneto, IN R+70
- Vera Cruz, IN R+70
- Poling, IN R+67
- Montpelier, IN R+58
- Bluffton, IN R+51
- Liberty Center, IN R+70
Cities with Similar Populations
- Youngstown, IN R+33
- Johnsburg, IN R+52
- Jennings, KS R+72
- Middleton, OK R+69
- Non, OK R+71
- Kentuckytown, TX R+69
- Meador, KY R+65
- North Branch, WI R+38
- Bridgeway, WV R+60
- Covena, GA R+67
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.