Costilla County leans Democratic by roughly 20 points: about 60% of voters vote Democratic and 40% Republican.
About 68% of adults in Costilla County typically vote, above the U.S. average of about 62%. Among adults in Costilla County, ~41% vote Democratic, ~27% Republican, and ~32% don't vote. The map below shows estimated turnout by block group.
How Costilla County compares
Among counties within 50 miles, Costilla County is the most Democratic-leaning.
Costilla County runs about 8 points more Democratic than Colorado as a whole.
Politics vary noticeably by city within Costilla County. The southeast side runs the most Democratic (D+38) and the northwest side runs the most Republican (Even), a spread of about 39 points.
Why Costilla County leans the way it does
Density, race composition, education, and family structure all sit close to their national averages in Costilla County. The lean here lands roughly where demographic data alone would predict.
Never-married share, developed land, and voter turnout
Places that combine a low never-married share and a rural land-use pattern tend to turn out at a higher rate, as Costilla County, CO does.
Why turnout in Costilla County looks the way it does
Areas with limited routine healthcare access turn out at lower rates. Costilla County is in the bottom quarter nationally for routine-care measures such as insurance coverage, preventive screenings, and dental visits. Learn more about the findings and methodology on the political spectrum map.
Nearby Counties
- Alamosa County, CO R+3
- Conejos County, CO R+25
- Huerfano County, CO R+7
- Rio Grande County, CO R+22
- Las Animas County, CO R+13
- Saguache County, CO D+5
- Custer County, CO R+33
- Colfax County, NM R+10
- Taos County, NM D+42
- Fremont County, CO R+25
Counties with Similar Populations
- Osborne County, KS R+74
- Baca County, CO R+69
- Lewis County, ID R+60
- Baylor County, TX R+66
- Hanson County, SD R+72
- Mercer County, MO R+70
- Sheridan County, MT R+58
- Hardeman County, TX R+60
- Roger Mills County, OK R+83
- Kimball County, NE R+68
Sources and methodology
Precinct-level voting records used to fit the model come from Colorado 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.