electionsmcp › 2028 races › U.S. Senate › Iowa
2028 Iowa U.S. Senate Race
A visual scenario calculator for Iowa's 2028 Senate contest — model swing and turnout down to the precinct, then roll it up to control of the chamber.
Office
U.S. Senate
Seat class
Class III
On the ballot
2028
Current hold
Republican
Both of Iowa's U.S. Senate seats are currently Republican-held. The seat on the ballot in 2028 is Iowa's Class III seat; the state's other seat (Class II, Republican) is not up this cycle. Every race in electionsmcp is built from the same atoms: 163,925 U.S. precincts with 2024 results, so Iowa's map starts from how the state actually voted.
Model the Iowa Senate race in five steps
- Set the candidates. Name the contenders for the Iowa Senate race (or keep the generic Democrat / Republican defaults). The map starts from real 2024 results in every precinct.
- Apply a swing. Move vote share statewide, or by demographic cohort, with a slider. The map and the running tally recompute instantly.
- Model turnout. Mobilize or depress turnout for any group — turnout and persuasion are modeled separately, the way a real campaign thinks about them.
- Drill to precincts. Zoom from the state down to individual precincts and override any of them by hand.
- Roll up & share. Roll the result up to chamber control, then publish a shareable, frozen link to your scenario.
What you can change
Persuasion (vote share) and turnout (mobilization) are modeled separately — statewide, by demographic cohort, by county, or precinct by precinct. Then roll up the seat into the national picture: how this race moves the Senate's 51-seat majority threshold.