Daniel Biss
Democratic
U.S. House · open seat · All Illinois races
Illinois District 9
Solid D
Daniel Biss
Democratic
100 in 100
chance of winning, out of 100
John Elleson
Republican
0 in 100
Daniel Biss wins in 100 of 100 simulations.
There are no qualifying public polls yet, so the forecast leans on fundamentals; partisan lean, the national environment and incumbency point to Daniel Biss +47.6.
Where the result could land
Every simulated outcome, grouped in 2-point steps. Projected margin Biss +47.7; 80 in 100 fall between Biss +40.3 and Biss +55.0.
The candidates
No biography on file yet.
John Elleson
Republican
Ballot list and short bios from Wikipedia (CC BY-SA); websites from Wikidata.
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Polls
No public polls have tested Daniel Biss against John Elleson yet.
No polls of this matchup yet, so there is no polling average. The forecast relies on fundamentals.
Chance of winning over time
How this race’s odds have moved as polls and the national environment changed.
Out of 100. Today: Biss 100, Elleson 0.
What’s driving the forecast
The model blends each estimate by how much to trust it right now. Polls get 0% of the weight, 15 days out.
| Polling average (after adjustments) | — | no polls |
| Partisan lean (Cook PVI, 2026 lines) | D+19.0 | roughly 38 points of margin vs. the nation |
| National environment | D+9.6 | generic ballot + presidential approval |
| Incumbency | none | open seat or incumbent not on ballot |
| Fundamentals estimate | Biss +47.6 | ±6 typical error |
| Expert ratings (average) | — | used only in the “+ Expert ratings” version |
| Forecast | Biss +47.6 | ±5.7 standard deviation, including 2.3 for movement before Election Day |
All three versions
- Polls only: Daniel Biss 100 in 100 (Solid D)
- Polls + fundamentals: Daniel Biss 100 in 100 (Solid D)
- Polls + fundamentals + experts: Daniel Biss 100 in 100 (Solid D)
Rules and notes
- Incumbent retiring
House races, closest first · this is #300 of 421