98103 is a Democratic stronghold. About 89% of voters here vote Democratic and 11% Republican.
About 77% of adults in 98103 typically vote, above the U.S. average of about 62%. Among adults in 98103, ~68% vote Democratic, ~9% Republican, and ~23% don't vote. The map below shows estimated turnout by block group.
How 98103 compares
Among zip codes within 15 miles, 98103 leans more Democratic than 63 of 66 neighbors.
98103 runs about 60 points more Democratic than Washington as a whole.
Politics vary noticeably by block within 98103. The southeast side is the most Democratic-leaning (D+84) and the northwest side is the least Democratic-leaning (D+73), a spread of about 12 points.
Why 98103 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 98103, not a ranked or complete list of what matters most.
Dense areas vote Democratic. About 97% of residents in 98103 live in densely developed areas, about 61 points above the U.S. average of 36%. High college attainment predicts Democratic voting, and 98103 sits in the top quarter (about 78%, in the top fraction of zip codes). A high never-married share predicts Democratic voting, and about 49% of adults in 98103 have never been married, above 95% of zip codes.
Population density and Democratic lean
Places with high population density tend to lean Democratic; 98103, WA sits in the top tenth nationally on this measure.
Why turnout in 98103 looks the way it does
Areas with strong routine healthcare access turn out at higher rates. 98103 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 76%, about 16 points above the U.S. average of 60%. High high-school completion lines up with higher turnout, and about 98% of adults in 98103 have completed high school, above 96% of zip codes. 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.