98178 leans heavily Democratic by roughly 50 points: about 75% of voters vote Democratic and 25% Republican.
About 58% of adults in 98178 typically vote, near the U.S. average of about 62%. Among adults in 98178, ~44% vote Democratic, ~14% Republican, and ~42% don't vote. The map below shows estimated turnout by block group.
How 98178 compares
Among zip codes within 15 miles, 98178 leans more Democratic than 36 of 61 neighbors.
98178 runs about 32 points more Democratic than Washington as a whole.
Politics vary noticeably by block within 98178. The north side is the most Democratic-leaning (D+59) and the southwest side is the least Democratic-leaning (D+42), a spread of about 16 points.
Why 98178 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 98178, not a ranked or complete list of what matters most.
Dense areas vote Democratic. About 95% of residents in 98178 live in densely developed areas, about 59 points above the U.S. average of 36%. High college attainment predicts Democratic voting, and 98178 sits in the top quarter (about 36%, above 76% of zip codes). A high never-married share predicts Democratic voting, and about 35% of adults in 98178 have never been married, above 79% of zip codes.
Population density and Democratic lean
Places with high population density tend to lean Democratic; 98178, WA sits in the top tenth nationally on this measure.
Why turnout in 98178 looks the way it does
Renters vote less often than owners. About 34% of households in 98178 rent, about 9 points above the U.S. average of 25%. 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.