83203 leans Democratic by roughly 28 points: about 64% of voters vote Democratic and 36% Republican.
About 59% of adults in 83203 typically vote, near the U.S. average of about 62%. Among adults in 83203, ~38% vote Democratic, ~21% Republican, and ~41% don't vote. The map below shows estimated turnout by block group.
How 83203 compares
Among zip codes within 15 miles, 83203 is the most Democratic-leaning.
83203 runs about 65 points more Democratic than Idaho as a whole. Idaho leans Republican overall, while 83203 is one of the few Democratic-leaning pockets.
Politics vary noticeably by block within 83203. The northwest side is the most Democratic-leaning (D+45) and the southwest side is the least Democratic-leaning (D+18), a spread of about 27 points.
Why 83203 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 83203, not a ranked or complete list of what matters most.
83203 votes against the grain of Idaho. Idaho leans Republican overall, while 83203 runs about 65 points more Democratic. A high never-married share predicts Democratic voting, and about 40% of adults in 83203 have never been married, above 87% of zip codes.
Walkability and Republican lean
Places with a low walkability score tend to lean Republican; 83203, ID sits in the bottom tenth nationally on this measure. A walkable street grid does not change how people vote; it mostly reflects how urban a place is.
Why turnout in 83203 looks the way it does
Areas with limited routine healthcare access turn out at lower rates. 83203 is in the bottom quarter nationally for routine-care measures such as insurance coverage, preventive screenings, and dental visits. High food insecurity lines up with lower turnout, and about 33% of adults in 83203 report food insecurity, above 96% of zip codes. High-crime urban areas turn out at lower rates, and 83203 sits in the top 15% on a violent-crime measure. 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.