97603 leans heavily Republican by roughly 38 points: about 31% of voters vote Democratic and 69% Republican.
About 75% of adults in 97603 typically vote, above the U.S. average of about 62%. Among adults in 97603, ~23% vote Democratic, ~52% Republican, and ~25% don't vote. The map below shows estimated turnout by block group.
How 97603 compares
Among zip codes within 15 miles, 97603 leans more Republican than 1 of 5 neighbors.
97603 runs about 52 points more Republican than Oregon as a whole. Oregon leans Democratic overall, while 97603 is one of the few Republican-leaning pockets.
Politics vary noticeably by block within 97603. The south side is the most Republican-leaning (R+55) and the northwest side is the least Republican-leaning (R+23), a spread of about 32 points.
Why 97603 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 97603, not a ranked or complete list of what matters most.
97603 votes against the grain of Oregon. Oregon leans Democratic overall, while 97603 runs about 52 points more Republican. Dense places usually vote Democratic, but 97603 runs against that pattern.
Paved land cover and Democratic lean
Places with extensive paved surfaces tend to lean Democratic; 97603, OR sits in the top quarter 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 97603 looks the way it does
Turnout in 97603 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 Zip Codes
Zip Codes with Similar Populations
Sources and methodology
Precinct-level voting records used to fit the model come from Oregon Secretary of State, Elections Division, 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.