Senate / IdahoIdaho Senate 2026 · seat held by Republicans (incumbent running)
Jim Risch is heavily favored to win Idaho
Todd Achilles (I)5%Independent
Jim Risch95%Republican · incumbent
Forecast marginR+11.680%: R+21.0 to R+3.0
Tipping point–chance it decides control
Cook ratingSolid ROct 20
2024 presidentR+36.5nation R+1.5
Polls
Each dot is a poll after adjustment; grey ticks show where it was as publishedDot size shows the weight a poll gets. The line is the model's polling average, with its 80% band. The bar at right is the 80% range of the forecast on election day.
Range of outcomes
Independent margin across simulationsTodd Achilles (I) wins in 5% of simulations (about 1 in 20 for the underdog). Median margin R+12.0.
Chance of winning over time
Daily reruns of the modelEach day is a fresh run of today's model using only the polls that had finished by the day before. Daily runs since Jul 1.
How the forecast is built
Independent races have no partisan baseline, so the forecast leans on polling, with 3 points of extra uncertainty for how independents perform against their polls.
What this race means for control
Because polling errors are correlated, a win here usually comes with wins elsewhere.
Every poll in the model
| Pollster | Field end | Sample | Published | House effect | Adjusted | Weight |
|---|---|---|---|---|---|---|
| VoteNexus D internal | Oct 22 | 700 LV | R+6.0 | D+0.8 | R+9.1 | 0.34 |
| Peak Insights | Sep 30 | 500 LV | R+25.0 | R+10.4 | R+22.8 | 0.66 |
| Advanced Targeting Research | Sep 16 | 700 RV | I+6.1 | D+4.7 | I+2.9 | 0.71 |
| Peak Insights | Aug 13 | 500 LV | R+34.0 | R+10.4 | R+35.5 | 0.29 |
| The Bullfinch Group | Aug 7 | 608 LV | R+4.0 | D+1.7 | R+7.1 | 0.78 |