Portsmouth, Portland, OR Political Map | Democrat & Republican Areas in Portsmouth

By the BestNeighborhood data science team. Last updated May 2026.

Portsmouth is a Democratic stronghold. About 81% of voters here vote Democratic and 19% Republican.

 

About 58% of adults in Portsmouth typically vote, near the U.S. average of about 62%. Among adults in Portsmouth, ~47% vote Democratic, ~11% Republican, and ~42% don't vote. The map below shows estimated turnout by block group.

How Portsmouth compares

Among neighborhoods within 5 miles, Portsmouth leans more Democratic than 6 of 21 neighbors.

Portsmouth runs about 47 points more Democratic than Oregon as a whole.

Politics vary noticeably by block within Portsmouth. The southeast side is the most Democratic-leaning (D+75) and the south side is the least Democratic-leaning (D+57), a spread of about 17 points.

Why Portsmouth leans the way it does

This analysis examined 14,881 data points per neighborhood to find what predicts political lean and turnout. The items below are a few correlations that stood out for Portsmouth, not a ranked or complete list of what matters most.

Areas with many never-married adults vote Democratic. About 49% of adults in Portsmouth have never been married, about 20 points above the U.S. average of 29%.

Paved land cover and Democratic lean

Places with extensive paved surfaces tend to lean Democratic; Portsmouth, Portland, 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 Portsmouth looks the way it does

Turnout in Portsmouth 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.

All Local Stats

Home Services

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.