83651 leans Republican by roughly 30 points: about 35% of voters vote Democratic and 65% Republican.
About 57% of adults in 83651 typically vote, near the U.S. average of about 62%. Among adults in 83651, ~20% vote Democratic, ~37% Republican, and ~43% don't vote. The map below shows estimated turnout by block group.
How 83651 compares
Among zip codes within 15 miles, 83651 leans more Republican than 6 of 16 neighbors.
83651 runs about 7 points more Democratic than Idaho as a whole.
Politics vary noticeably by block within 83651. The southwest side is the most Republican-leaning (R+42) and the southeast side is the least Republican-leaning (R+9), a spread of about 32 points.
Why 83651 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 83651, not a ranked or complete list of what matters most.
83651 votes Republican even though it is densely developed (about 91%, far above the Idaho average of 18%). State and regional patterns outweigh the Democratic lean that density usually predicts here.
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 83651, ID does.
Why turnout in 83651 looks the way it does
Areas with limited routine healthcare access turn out at lower rates. 83651 is in the bottom quarter nationally for routine-care measures such as insurance coverage, preventive screenings, and dental visits. 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.