Gilliam County leans heavily Republican by roughly 48 points: about 26% of voters vote Democratic and 74% Republican.
About 64% of adults in Gilliam County typically vote, near the U.S. average of about 62%. Among adults in Gilliam County, ~17% vote Democratic, ~47% Republican, and ~36% don't vote. The map below shows estimated turnout by block group.
How Gilliam County compares
Among counties within 50 miles, Gilliam County leans more Republican than 2 of 4 neighbors.
Gilliam County runs about 62 points more Republican than Oregon as a whole. Oregon leans Democratic overall, while Gilliam County is one of the few Republican-leaning pockets.
Why Gilliam County leans the way it does
This analysis examined 14,881 data points per county to find what predicts political lean and turnout. The items below are a few correlations that stood out for Gilliam County, not a ranked or complete list of what matters most.
Gilliam County votes against the grain of Oregon. Oregon leans Democratic overall, while Gilliam County runs about 62 points more Republican.
Developed land and Republican lean
Places with a rural land-use pattern tend to lean Republican; Gilliam County, OR sits in the bottom tenth nationally on this measure. Developed land does not change how people vote; it mostly reflects how urban a place is.
Why turnout in Gilliam County looks the way it does
Turnout in Gilliam County 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 Counties
- Sherman County, OR R+59
- Morrow County, OR R+36
- Wheeler County, OR R+51
- Wasco County, OR R+14
- Klickitat County, WA R+11
- Umatilla County, OR R+34
- Hood River County, OR D+24
- Benton County, WA R+21
- Yakima County, WA R+6
- Jefferson County, OR R+26
Counties with Similar Populations
- Jeff Davis County, TX R+51
- Clark County, KS R+73
- Worth County, MO R+64
- Judith Basin County, MT R+62
- Menard County, TX R+53
- Liberty County, MT R+56
- Buffalo County, SD D+24
- Keweenaw County, MI Even
- Meagher County, MT R+58
- Wheatland County, MT R+66
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.