Round Rock is a Democratic stronghold. About 81% of voters here vote Democratic and 19% Republican.
About 85% of adults in Round Rock typically vote, above the U.S. average of about 62%. Among adults in Round Rock, ~69% vote Democratic, ~16% Republican, and ~15% don't vote. The map below shows estimated turnout by block group.
How Round Rock compares
Among cities within 25 miles, Round Rock leans more Democratic than 5 of 7 neighbors.
Round Rock runs about 68 points more Democratic than Arizona as a whole. Arizona leans Republican overall, while Round Rock is one of the few Democratic-leaning pockets.
Why Round Rock 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 Round Rock, not a ranked or complete list of what matters most.
Round Rock votes against the grain of Arizona. Arizona leans Republican overall, while Round Rock runs about 68 points more Democratic. A high never-married share predicts Democratic voting, and about 54% of adults in Round Rock have never been married, in the top fraction of cities.
Preventive-care access and voter turnout
Places with limited routine preventive-care access tend to turn out at a lower rate; Round Rock, AZ sits in the bottom tenth nationally on this measure. Dental visits do not drive turnout; the rate reflects income, insurance, and healthcare access, which line up with who votes.
Why turnout in Round Rock looks the way it does
Areas with limited routine healthcare access turn out at lower rates. Round Rock is in the bottom quarter nationally for routine-care measures such as insurance coverage, preventive screenings, and dental visits. The dental-visit rate here is about 38%, about 16 points below the Arizona average of 54%. Learn more about the findings and methodology on the political spectrum map.
Nearby Cities
- Upper Wheatfields, AZ D+58
- Rock Point, AZ D+61
- Lukachukai, AZ D+64
- Many Farms, AZ D+61
- Red Valley, AZ D+36
- Tsaile, AZ D+62
- Rough Rock, AZ D+63
- Red Mesa, AZ D+54
- Chinle, AZ D+61
- Wheatfields, AZ D+61
Cities with Similar Populations
- Elwell, MI R+49
- Morrisonville, IL R+61
- Del Rio, TN R+68
- Waterloo, CA R+40
- Egan, LA R+85
- Valley Lee, MD R+14
- Blue River, WI R+27
- Massieville, OH R+58
- Hopewell, PA R+75
- Hickory Grove, SC R+67
Sources and methodology
Precinct-level voting records used to fit the model come from Arizona 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.