2026 forecast · Illinois 12th

Mike Bost is all but certain to win Illinois's 12th District.

Julie Fortier vs Mike Bost. The model has Bost ahead by 46.2 points, winning 100 percent of 2,000 simulated elections.

Safe RModel R +46.2Updated October 22, 2026
Julie Fortier
Democrat
26.9%
83,063 projected votes
Mike Bost
Republican
73.1%
225,553 projected votes
100%Bost
0%Fortier
Bost all but certainEach square is one simulated election night, Bost wins about 100 of 100
RatingSafe R100% chance for Bost
Model marginR +46.2No polls in the race
80 percent rangeR +40.1 to R +52.22,000 simulations
Projected votes308,616Bost 73.1%

The district map

Every district in the state, shaded by its rating

Illinois districts

17 districts
Safe DLikely DLean DToss upLean RLikely RSafe R

Vote share

Each candidate's projected share and the range of 80 percent of simulations

Julie FortierDemocrat · 0% to win
26.9%
Mike BostRepublican · 100% to win
73.1%

Scale runs from 25 to 75 percent. The dot is the forecast, the band is the 80 percent range and the brighter tick marks 50 percent.

Projected district vote

308,616 votes
CandidateVotesShare
Mike Bost R225,55373.1%
Julie Fortier D83,06326.9%
Total308,616100%

Each candidate's expected vote in the On Point simulation, at the forecast's projected turnout.

The trend

Each side's chance of winning over the forecast's recent updates

0%25%50%75%100%0% Fortier100% Bost15 updates agoToday

Polling

Every poll in the average, and how the model reads it

The Illinois governor polling average
30%35%40%45%50%55%60%MayJunJulAugSepOct54.0Pritzker34.0Bailey
The line is the On Point average: a robust LOWESS fit through the polls, weighted by recency, sample, voter screen and pollster grade, refit three times so outliers count for lessDot size is each poll's weight todayHover or use the arrow keys to read any day
What moves the average today
Public Policy Polling for Chicago News WeeklyOct 1 · 569 LV · D->99%Pritzker +20.0

This is the same On Point polling average as the full average page. The forecast reads the polls through its own Election Day projection, shown as the On Point average in the table below, and blends it with partisan lean and fundamentals.

Polls of the race

Full average
PollsterSampleAgeMargin
On Point averageWeighted averageNo polls

Each margin is the poll as the pollster published it. The forecast counts every poll after its house effect and the undecided split, which is what the trail above shows; hover a margin for the counted value. Lean R and Lean D mark partisan leaning firms.

Model margin
Bost +46.2
Chance of winning
Julie Fortier0%
Mike Bost100%
Simulated vote
Julie Fortier26.9%
Mike Bost73.1%
How the model gets there
Partisan leanD +43.0
FundamentalsR +46.3
With pollsR +46.5
Early vote turnoutD +0.3
With early voteR +46.2

Read from 0 ballots cast so far in Illinois, against the party mix the forecast expected of them, with similar states and primary turnout. Early vote tracker

How we got here

From the state's partisan lean to the forecast, one stage at a time

D +56R +56Partisan leanthe state's baselineD +43.0Fundamentalsapproval, economy, candidatesR +46.3With pollsno pollsR +46.5With early voteturnout so farR +46.2
Methodology
Every county is rebuilt by simulating voters going to the polls, 2,000 times, from On Point Polling survey data, past results, and the polling average. How the model works.