99338 leans heavily Republican by roughly 32 points: about 34% of voters vote Democratic and 66% Republican.
About 84% of adults in 99338 typically vote, above the U.S. average of about 62%. Among adults in 99338, ~29% vote Democratic, ~55% Republican, and ~16% don't vote. The map below shows estimated turnout by block group.
How 99338 compares
Among zip codes within 15 miles, 99338 leans more Republican than 6 of 8 neighbors.
99338 runs about 51 points more Republican than Washington as a whole. Washington leans Democratic overall, while 99338 is one of the few Republican-leaning pockets.
Politics vary noticeably by block within 99338. The west side is the most Republican-leaning (R+47) and the east side is the least Republican-leaning (R+22), a spread of about 25 points.
Why 99338 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 99338, not a ranked or complete list of what matters most.
99338 votes against the grain of Washington. Washington leans Democratic overall, while 99338 runs about 51 points more Republican. Dense places usually vote Democratic, but 99338 runs against that pattern. A high family-household share predicts Republican voting, and about 79% of households in 99338 are family households, above 90% of zip codes.
Preventive-care access and voter turnout
Places with strong routine preventive-care access tend to turn out at a higher rate; 99338, WA sits in the top quarter 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 99338 looks the way it does
Areas with strong routine healthcare access turn out at higher rates. 99338 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 70%, about 10 points above the U.S. average of 60%. 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 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.