San Mateo leans slightly Republican by roughly 8 points: about 46% of voters vote Democratic and 54% Republican.
About 44% of adults in San Mateo typically vote, below the U.S. average of about 62%. Among adults in San Mateo, ~20% vote Democratic, ~24% Republican, and ~56% don't vote. The map below shows estimated turnout by block group.
How San Mateo compares
Among cities within 25 miles, San Mateo leans more Republican than 12 of 17 neighbors.
San Mateo runs about 14 points more Republican than New Mexico as a whole. New Mexico leans Democratic overall, while San Mateo is one of the few Republican-leaning pockets.
Politics vary noticeably by neighborhood within San Mateo. The west side runs the most Democratic (D+17) and the south side runs the most Republican (R+10), a spread of about 27 points.
Why San Mateo 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 San Mateo, not a ranked or complete list of what matters most.
Rural areas vote Republican. About 1% of residents in San Mateo live in densely developed areas, about 16 points below the New Mexico average of 18%. San Mateo runs against the grain of New Mexico, a Republican-leaning pocket in a Democratic-leaning state.
Population density, never-married share, and Republican lean
Places that combine low population density and a never-married-heavy adult population tend to lean Republican, as San Mateo, NM does.
Why turnout in San Mateo looks the way it does
Areas with limited routine healthcare access turn out at lower rates. San Mateo is in the bottom quarter nationally for routine-care measures such as insurance coverage, preventive screenings, and dental visits. High food insecurity lines up with lower turnout, and about 25% of adults in San Mateo report food insecurity, above 90% of cities. Learn more about the findings and methodology on the political spectrum map.
Nearby Cities
- San Fidel, NM D+21
- Grants, NM R+9
- Milan, NM R+12
- Bluewater, NM R+20
- Cubero, NM D+16
- North Acomita Village, NM D+64
- Seboyeta, NM R+10
- San Rafael, NM R+39
Cities with Similar Populations
- Agnes, MO R+71
- Myron, AR R+66
- Capehart, WV R+70
- Aonia, GA R+57
- Collison, IL R+56
- Hyattville, WY R+76
- Breeden, WV R+81
- Peacock Corners, MD R+35
- Pleasant Hill, AL R+84
- Wichita, IA R+49
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Sources and methodology
Precinct-level voting records used to fit the model come from New Mexico Secretary of State, Bureau of 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.