Clark County leans slightly Democratic by roughly 6 points: about 53% of voters vote Democratic and 47% Republican.
About 75% of adults in Clark County typically vote, above the U.S. average of about 62%. Among adults in Clark County, ~40% vote Democratic, ~35% Republican, and ~25% don't vote. The map below shows estimated turnout by block group.
How Clark County compares
Among counties within 50 miles, Clark County leans more Democratic than 4 of 8 neighbors.
Clark County runs about 11 points more Republican than Washington as a whole.
Politics vary noticeably by city within Clark County. The southwest side runs the most Democratic (D+45) and the northeast side runs the most Republican (R+28), a spread of about 73 points.
Why Clark 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 Clark County, not a ranked or complete list of what matters most.
Dense areas vote Democratic. About 78% of residents in Clark County live in densely developed areas, about 42 points above the U.S. average of 36%. High college attainment predicts Democratic voting, and Clark County sits in the top quarter (about 33%, above 83% of counties).
Population density and Democratic lean
Places with high population density tend to lean Democratic; Clark County, WA sits in the top tenth nationally on this measure.
Why turnout in Clark County looks the way it does
Areas with strong routine healthcare access turn out at higher rates. Clark County 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 66%, about 6 points above the U.S. average of 60%. Learn more about the findings and methodology on the political spectrum map.
Nearby Counties
- Multnomah County, OR D+52
- Washington County, OR D+32
- Clackamas County, OR D+13
- Columbia County, OR R+18
- Skamania County, WA R+13
- Cowlitz County, WA R+18
- Yamhill County, OR R+5
- Hood River County, OR D+24
- Marion County, OR D+3
- Wahkiakum County, WA R+19
Counties with Similar Populations
- Lake County, IN D+14
- Morris County, NJ Even
- Richmond County, NY R+21
- Ada County, ID R+8
- Polk County, IA D+12
- Kane County, IL D+13
- Sonoma County, CA D+42
- Adams County, CO D+11
- Washoe County, NV D+3
- Camden County, NJ D+30
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Sources and methodology
Precinct-level voting records used to fit the model come from Washington 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.