83705 leans Democratic by roughly 20 points: about 60% of voters vote Democratic and 40% Republican.
About 65% of adults in 83705 typically vote, near the U.S. average of about 62%. Among adults in 83705, ~39% vote Democratic, ~26% Republican, and ~35% don't vote. The map below shows estimated turnout by block group.
How 83705 compares
Among zip codes within 15 miles, 83705 leans more Democratic than 9 of 13 neighbors.
83705 runs about 56 points more Democratic than Idaho as a whole. Idaho leans Republican overall, while 83705 is one of the few Democratic-leaning pockets.
Politics vary noticeably by block within 83705. The north side is the most Democratic-leaning (D+38) and the southwest side is the least Democratic-leaning (D+9), a spread of about 28 points.
Why 83705 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 83705, not a ranked or complete list of what matters most.
Dense areas vote Democratic. More than 99% of residents in 83705 live in densely developed areas, about 63 points above the U.S. average of 36%. High college attainment predicts Democratic voting, and 83705 sits in the top quarter (about 40%, above 81% of zip codes). 83705 runs against the grain of Idaho, a Democratic-leaning pocket in a Republican-leaning state.
Population density and Democratic lean
Places with high population density tend to lean Democratic; 83705, ID sits in the top tenth nationally on this measure.
Why turnout in 83705 looks the way it does
Turnout in 83705 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 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.