electionsmcp › 2028 races › U.S. Senate › Illinois
2028 Illinois U.S. Senate Race
A visual scenario calculator for Illinois's 2028 Senate contest — model swing and turnout across the finest supported local grain, then roll it up to control of the chamber.
Model the Illinois Senate race →
Office
U.S. Senate
Seat class
Class III
On the ballot
2028
Current hold
Democratic
Both of Illinois's U.S. Senate seats are currently Democratic-held. The seat on the ballot in 2028 is Illinois's Class III seat; the state's other seat (Class II, Democratic) is not up this cycle. The canonical mixed-grain 2024 presidential baseline uses verified precinct or reporting-unit results where supported, with declared county/state fallbacks elsewhere.
Model the Illinois Senate race in five steps
- Set the candidates. Name the contenders for the Illinois Senate race (or keep the generic Democrat / Republican defaults). The map starts from the canonical mixed-grain 2024 presidential baseline.
- 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.
- Explore local geography. Zoom from the state through counties to the finest supported reporting grain and adjust the places available in the model.
- Roll up & share. Roll the result up to chamber control, then share the exact versioned scenario.
Open Illinois in the simulator →
What you can change
Persuasion (vote share) and turnout (mobilization) are modeled separately — statewide, by demographic cohort, by county, and at the supported local reporting grain. Then roll up the seat into the national picture: how this race moves the Senate's 51-seat majority threshold.