Boise, ID Political Map | Democrat & Republican Areas in Boise

By the BestNeighborhood data science team. Last updated May 2026.

Boise leans Republican by roughly 20 points: about 40% of voters vote Democratic and 60% Republican.

 

About 72% of adults in the Boise area typically vote, above the U.S. average of about 62%. Among adults in the Boise area, ~29% vote Democratic, ~43% Republican, and ~28% don't vote. The map below shows estimated turnout by block group.

How Boise compares

Among cities within 25 miles, Boise leans more Republican than 1 of 19 neighbors.

Boise runs about 16 points more Democratic than Idaho as a whole.

Politics vary noticeably by neighborhood within Boise. The east side runs the most Democratic (D+25) and the northwest side runs the most Republican (R+48), a spread of about 73 points.

Why Boise 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 Boise, not a ranked or complete list of what matters most.

Boise votes Republican even though it is densely developed (about 79%, far above the Idaho average of 18%). State and regional patterns outweigh the Democratic lean that density usually predicts here.

Walkability and Democratic lean

Places with a highly walkable street grid tend to lean Democratic; Boise, ID sits in the top 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 Boise looks the way it does

Areas with strong routine healthcare access turn out at higher rates. Boise 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 69%, about 9 points above the U.S. average of 60%. Learn more about the findings and methodology on the political spectrum map.

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.