IL-09 House forecast
Safe Dem2024 lines
Polls close . Statewide at 7:00 PM local time
Biss 97% chance
- Daniel Biss (D)-1% past 7 days97%
- John Elleson (R)+2% past 7 days3%
Chance over time
- Biss97%
- Elleson3%
Chance over time, past month: Biss from 95% to 97%; Elleson from 5% to 3%.
| Date | Biss | Elleson |
|---|---|---|
| Sep 22, 2026 | 96% | 5% |
| Sep 29, 2026 | 96% | 5% |
| Oct 6, 2026 | 97% | 2% |
| Oct 14, 2026 | 98% | 1% |
| Oct 21, 2026 | 97% | 3% |
Projected margin
Most likely Biss by 45–50 · 8 in 10: Biss +32 to Biss +58
| Margin | Chance |
|---|---|
| Elleson wins | 1% |
| Biss by 0–20 | 2% |
| Biss by 20–30 | 4% |
| Biss by 30–35 | 6% |
| Biss by 35–40 | 6% |
| Biss by 40–45 | 22% |
| Biss by 45–50 | 24% |
| Biss by 50–55 | 14% |
| Biss by 55–60 | 17% |
| Biss by 60+ | 3% |