98003 leans heavily Democratic by roughly 32 points: about 66% of voters vote Democratic and 34% Republican.
About 55% of adults in 98003 typically vote, below the U.S. average of about 62%. Among adults in 98003, ~36% vote Democratic, ~19% Republican, and ~45% don't vote. The map below shows estimated turnout by block group.
How 98003 compares
Among zip codes within 15 miles, 98003 leans more Democratic than 35 of 57 neighbors.
98003 runs about 14 points more Democratic than Washington as a whole.
Politics vary noticeably by block within 98003. The north side is the most Democratic-leaning (D+39) and the southeast side is the least Democratic-leaning (D+18), a spread of about 20 points.
Why 98003 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 98003, not a ranked or complete list of what matters most.
Dense areas vote Democratic. About 95% of residents in 98003 live in densely developed areas, about 58 points above the U.S. average of 36%. A high never-married share predicts Democratic voting, and about 38% of adults in 98003 have never been married, above 85% of zip codes.
Population density and Democratic lean
Places with high population density tend to lean Democratic; 98003, WA sits in the top tenth nationally on this measure.
Why turnout in 98003 looks the way it does
Areas with limited routine healthcare access turn out at lower rates. 98003 is in the bottom quarter nationally for routine-care measures such as insurance coverage, preventive screenings, and dental visits. Renters vote less often than owners, and about 51% of households in 98003 rent, about 26 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.