Kauai County leans Democratic by roughly 20 points: about 60% of voters vote Democratic and 40% Republican.
About 58% of adults in Kauai County typically vote, near the U.S. average of about 62%. Among adults in Kauai County, ~35% vote Democratic, ~23% Republican, and ~42% don't vote. The map below shows estimated turnout by block group.
How Kauai County compares
Politically, Kauai County sits close to the rest of Hawaii.
Politics vary noticeably by city within Kauai County. The southeast side is the most Democratic-leaning (D+29) and the northwest side is the least Democratic-leaning (D+16), a spread of about 13 points.
Why Kauai 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 Kauai County, not a ranked or complete list of what matters most.
Areas with high college attainment vote Democratic. About 30% of adults in Kauai County hold a bachelor's degree, above 77% of counties. A high never-married share predicts Democratic voting, and about 34% of adults in Kauai County have never been married, above 80% of counties.
Preventive-care access and voter turnout
Places with strong routine preventive-care access tend to turn out at a higher rate; Kauai County, HI sits in the top tenth nationally on this measure. Dental visits do not drive turnout; the rate reflects income, insurance, and healthcare access, which line up with who votes.
Why turnout in Kauai County looks the way it does
Crowded housing lines up with lower turnout. About 7% of homes in Kauai County have more than one occupant per room, above 96% of counties. Strong routine healthcare access lines up with higher turnout, and Kauai County sits in the top quarter on routine-care measures. Learn more about the findings and methodology on the political spectrum map.
Nearby Counties
- Honolulu County, HI D+18
- Maui County, HI D+19
- Hawaii County, HI D+20
- Aleutians West Census Area, AK Even
- Aleutians East Borough, AK D+6
- Mendocino County, CA D+23
- Humboldt County, CA D+27
- Sonoma County, CA D+42
- Marin County, CA D+48
Counties with Similar Populations
- Putnam County, FL R+42
- Grand Forks County, ND R+8
- Lauderdale County, MS R+5
- Fauquier County, VA R+19
- McKinley County, NM D+27
- Robertson County, TN R+46
- Christian County, KY R+21
- Tooele County, UT R+45
- Scioto County, OH R+47
- Lonoke County, AR R+52
Sources and methodology
Precinct-level voting records used to fit the model come from Hawaii Office of 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. Some land-use inputs for Hawaii, including walkability and the environmental-justice index, are estimated rather than measured, so the figures here carry added uncertainty. Full methodology and findings: political spectrum map.
Methodology reviewed by the BestNeighborhood data team. Last updated May 2026.