99337 leans heavily Republican by roughly 30 points: about 35% of voters vote Democratic and 65% Republican.
About 74% of adults in 99337 typically vote, above the U.S. average of about 62%. Among adults in 99337, ~26% vote Democratic, ~48% Republican, and ~26% don't vote. The map below shows estimated turnout by block group.
How 99337 compares
Among zip codes within 15 miles, 99337 leans more Republican than 5 of 8 neighbors.
99337 runs about 49 points more Republican than Washington as a whole. Washington leans Democratic overall, while 99337 is one of the few Republican-leaning pockets.
Politics vary noticeably by block within 99337. The east side is the most Republican-leaning (R+43) and the north side is the least Republican-leaning (R+19), a spread of about 24 points.
Why 99337 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 99337, not a ranked or complete list of what matters most.
99337 votes against the grain of Washington. Washington leans Democratic overall, while 99337 runs about 49 points more Republican. Dense places usually vote Democratic, but 99337 runs against that pattern. A high family-household share predicts Republican voting, and about 76% of households in 99337 are family households, above 82% of zip codes.
Population density and Democratic lean
Places with high population density tend to lean Democratic; 99337, WA sits in the top quarter nationally on this measure.
Why turnout in 99337 looks the way it does
Turnout in 99337 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 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.