83340 leans Democratic by roughly 28 points: about 64% of voters vote Democratic and 36% Republican.
About 85% of adults in 83340 typically vote, above the U.S. average of about 62%. Among adults in 83340, ~54% vote Democratic, ~31% Republican, and ~15% don't vote. The map below shows estimated turnout by block group.
How 83340 compares
Among zip codes within 15 miles, 83340 leans more Democratic than 1 of 3 neighbors.
83340 runs about 64 points more Democratic than Idaho as a whole. Idaho leans Republican overall, while 83340 is one of the few Democratic-leaning pockets.
Politics vary noticeably by block within 83340. The southwest side is the most Democratic-leaning (D+35) and the east side is the least Democratic-leaning (D+21), a spread of about 14 points.
Why 83340 leans the way it does
This analysis examined 14,881 data points per zip code to find what predicts political lean and turnout. The items below are a few correlations that stood out for 83340, not a ranked or complete list of what matters most.
Areas with high college attainment vote Democratic. About 63% of adults in 83340 hold a bachelor's degree, about 35 points above the U.S. average of 28%. 83340 runs against the grain of Idaho, a Democratic-leaning pocket in a Republican-leaning state.
Preventive-care access and voter turnout
Places with strong routine preventive-care access tend to turn out at a higher rate; 83340, ID sits in the top tenth nationally on this measure. Dental visits do not drive turnout; the rate reflects income, insurance, and healthcare access, which line up with who votes.
Why turnout in 83340 looks the way it does
Areas with strong routine healthcare access turn out at higher rates. 83340 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 96% of adults in 83340 have completed high school, above 85% of zip codes. Learn more about the findings and methodology on the political spectrum map.
Nearby Zip Codes
Zip Codes with Similar Populations
Sources and methodology
Precinct-level voting records used to fit the model come from Idaho 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.