Sunnyvale leans Republican by roughly 18 points: about 41% of voters vote Democratic and 59% Republican.
About 65% of adults in Sunnyvale typically vote, near the U.S. average of about 62%. Among adults in Sunnyvale, ~27% vote Democratic, ~38% Republican, and ~35% don't vote. The map below shows estimated turnout by block group.
How Sunnyvale compares
Among cities within 25 miles, Sunnyvale leans more Republican than 31 of 62 neighbors.
Sunnyvale runs about 5 points more Republican than Texas as a whole.
Politics vary noticeably by neighborhood within Sunnyvale. The southwest side runs the most Democratic (D+14) and the northeast side runs the most Republican (R+26), a spread of about 40 points.
Why Sunnyvale 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 Sunnyvale, not a ranked or complete list of what matters most.
Sunnyvale votes Republican even though it is densely developed (about 48%, modestly above the Texas average of 35%). State and regional patterns outweigh the Democratic lean that density usually predicts here. A high family-household share predicts Republican voting, and about 84% of households in Sunnyvale are family households, above 96% of cities.
Paved land cover and Democratic lean
Places with extensive paved surfaces tend to lean Democratic; Sunnyvale, TX 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 Sunnyvale looks the way it does
Turnout in Sunnyvale 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 Cities
- Mesquite, TX D+18
- Balch Springs, TX D+26
- Heath, TX R+45
- Rowlett, TX R+6
- Forney, TX R+9
- Garland, TX D+15
- Seagoville, TX Even
- Rockwall, TX R+31
- McLendon-Chisholm, TX R+52
- Kleberg, TX D+21
Cities with Similar Populations
- Trinity, TX R+53
- Castroville, TX R+33
- Louisburg, KS R+39
- Mountainside, NJ Even
- Baldwin Harbor, NY D+39
- Tomahawk, WI R+28
- Wadesboro, NC D+22
- Monticello, FL R+17
- Beaverton, MI R+45
- Rocky Face, GA R+65
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Sources and methodology
Precinct-level voting records used to fit the model come from Texas 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.