99040 leans heavily Democratic by roughly 40 points: about 70% of voters vote Democratic and 30% Republican.
About 59% of adults in 99040 typically vote, near the U.S. average of about 62%. Among adults in 99040, ~41% vote Democratic, ~18% Republican, and ~41% don't vote. The map below shows estimated turnout by block group.
How 99040 compares
Among zip codes within 15 miles, 99040 is the most Democratic-leaning.
99040 runs about 23 points more Democratic than Washington as a whole.
Politics vary noticeably by block within 99040. The east side is the most Democratic-leaning (D+46) and the west side is the least Democratic-leaning (D+32), a spread of about 14 points.
Why 99040 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 99040, not a ranked or complete list of what matters most.
Areas with many never-married adults vote Democratic. About 39% of adults in 99040 have never been married, modestly above similar-sized zip codes (around 26%).
Preventive-care access and voter turnout
Places with limited routine preventive-care access tend to turn out at a lower rate; 99040, WA sits in the bottom tenth 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 99040 looks the way it does
High-crime urban areas turn out at lower rates, mostly because the housing stress common in those areas makes voting harder. 99040 sits in the top 15% nationally on a violent-crime measure. See CrimeGrade for more details. Limited routine healthcare access lines up with lower turnout, and 99040 sits in the bottom quarter on routine-care measures. Renters vote less often than owners, and about 38% of households in 99040 rent, compared to around 20% in nearby 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.