Washington County is a Republican stronghold. About 22% of voters here vote Democratic and 78% Republican.
About 71% of adults in Washington County typically vote, above the U.S. average of about 62%. Among adults in Washington County, ~16% vote Democratic, ~55% Republican, and ~29% don't vote. The map below shows estimated turnout by block group.
How Washington County compares
Among counties within 50 miles, Washington County leans more Republican than 2 of 5 neighbors.
Washington County runs about 20 points more Republican than Idaho as a whole.
Politics vary noticeably by city within Washington County. The east side is the most Republican-leaning (R+76) and the southwest side is the least Republican-leaning (R+45), a spread of about 31 points.
Why Washington County leans the way it does
This analysis examined 14,881 data points per county to find what predicts political lean and turnout. The items below are a few correlations that stood out for Washington County, not a ranked or complete list of what matters most.
Areas with many family households vote Republican. About 70% of households in Washington County are family households, above 79% of counties.
Paved land cover and Democratic lean
Places with extensive paved surfaces tend to lean Democratic; Washington County, ID sits above the national average on this measure. Paved ground does not change how people vote; it mostly reflects how urban and built-up a place is.
Why turnout in Washington County looks the way it does
Turnout in Washington County 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 Counties
- Payette County, ID R+57
- Malheur County, OR R+42
- Gem County, ID R+58
- Adams County, ID R+57
- Canyon County, ID R+40
- Valley County, ID R+41
- Baker County, OR R+41
- Boise County, ID R+50
- Ada County, ID R+8
- Owyhee County, ID R+63
Counties with Similar Populations
- Leslie County, KY R+76
- Gates County, NC R+29
- Crawford County, IN R+52
- Carbon County, MT R+38
- Custer County, NE R+68
- Bradley County, AR R+30
- Cumberland County, IL R+60
- Walsh County, ND R+46
- Mitchell County, IA R+36
- Bollinger County, MO R+70
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.