84121 leans Democratic by roughly 20 points: about 60% of voters vote Democratic and 40% Republican.
About 81% of adults in 84121 typically vote, above the U.S. average of about 62%. Among adults in 84121, ~49% vote Democratic, ~32% Republican, and ~19% don't vote. The map below shows estimated turnout by block group.
How 84121 compares
Among zip codes within 15 miles, 84121 leans more Democratic than 21 of 41 neighbors.
84121 runs about 41 points more Democratic than Utah as a whole. Utah leans Republican overall, while 84121 is one of the few Democratic-leaning pockets.
Politics vary noticeably by block within 84121. The northeast side runs the most Democratic (D+48) and the north side runs the most Republican (R+11), a spread of about 59 points.
Why 84121 leans the way it does
This analysis examined 14,881 data points per zip code to find what predicts political lean and turnout. The items below are a few correlations that stood out for 84121, not a ranked or complete list of what matters most.
Dense areas vote Democratic. About 96% of residents in 84121 live in densely developed areas, about 60 points above the U.S. average of 36%. High college attainment predicts Democratic voting, and 84121 sits in the top quarter (about 54%, above 91% of zip codes). 84121 runs against the grain of Utah, a Democratic-leaning pocket in a Republican-leaning state.
Paved land cover and Democratic lean
Places with extensive paved surfaces tend to lean Democratic; 84121, UT sits in the top tenth 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 84121 looks the way it does
Areas with strong routine healthcare access turn out at higher rates. 84121 is in the top quarter nationally for routine-care measures such as insurance coverage, preventive screenings, and dental visits. The dental-visit rate here is about 75%, about 15 points above the U.S. average of 60%. High high-school completion lines up with higher turnout, and about 97% of adults in 84121 have completed high school, above 90% of zip codes. Learn more about the findings and methodology on the political spectrum map.
Nearby Zip Codes
Zip Codes with Similar Populations
Sources and methodology
Precinct-level voting records used to fit the model come from Utah Lieutenant Governor's Office, 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.