Sumner leans slightly Democratic by roughly 6 points: about 53% of voters vote Democratic and 47% Republican.
About 69% of adults in Sumner typically vote, above the U.S. average of about 62%. Among adults in Sumner, ~37% vote Democratic, ~32% Republican, and ~31% don't vote. The map below shows estimated turnout by block group.
How Sumner compares
Among cities within 25 miles, Sumner leans more Democratic than 41 of 83 neighbors.
Sumner runs about 12 points more Republican than Washington as a whole.
Politics vary noticeably by neighborhood within Sumner. The southwest side runs the most Democratic (D+18) and the northwest side runs the most Republican (R+8), a spread of about 26 points.
Why Sumner leans the way it does
This analysis examined 14,881 data points per city to find what predicts political lean and turnout. The items below are a few correlations that stood out for Sumner, not a ranked or complete list of what matters most.
Dense areas vote Democratic. About 93% of residents in Sumner live in densely developed areas, about 57 points above the U.S. average of 36%. A high never-married share predicts Democratic voting, and about 33% of adults in Sumner have never been married, above 84% of cities.
Paved land cover and Democratic lean
Places with extensive paved surfaces tend to lean Democratic; Sumner, WA sits in the top tenth nationally on this measure. Paved ground does not change how people vote; it mostly reflects how urban and built-up a place is.
Why turnout in Sumner looks the way it does
Turnout in Sumner 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 Cities
- Lake Tapps, WA R+9
- Bonney Lake, WA R+5
- Edgewood, WA Even
- Puyallup, WA Even
- McMillin, WA Even
- Pacific, WA D+14
- Milton, WA D+5
- Prairie Ridge, WA R+17
- Algona, WA D+11
- Lakeland South, WA D+8
Cities with Similar Populations
- Lake Forest Park, WA D+56
- Brecksville, OH Even
- Bonham, TX R+42
- Bangor, PA R+27
- Fair Oaks, GA D+37
- Luling, LA R+39
- Millbury, MA Even
- Clayton, CA D+14
- Weigelstown, PA R+25
- Massena, NY R+13
All Local Stats
Home Services
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.