Idaho Senate
Incumbent: Jim Risch, currently Republican. No Democratic nominee: Todd Achilles (independent) stands on the Democratic side of the margin. The projection is the polling average alone, with a wider interval, because no independent-versus-Republican race is in the backtest.
The average over time
Each poll is first shifted by its sponsor's and its pollster's measured lean, then weighted by recency and track record. Sample size gets no weight: in 2,000-plus past races it predicted nothing about accuracy. Why.
What the fundamentals say
A regression on past Senate races, fit without looking at this year. The national environment term uses the generic ballot after its historical correction (D+5.3).
All 6 polls in the average
“Share” is how much of today’s average each poll supplies. It depends on recency, the pollster’s record, whether the poll screens for likely voters, and how many other polls the same firm has in the race. It does not depend on sample size.
| Dates | Pollster | Sample | Achilles | Risch | As published | Adjusted | Share of average | |
|---|---|---|---|---|---|---|---|---|
| Sep 13–16 | Advanced Targeting Research | 700 RV | 48 | 39 | I+9 | I+7.9 moved 1.1 toward R | 25% | source |
| Aug 11–13 | Moore Information GroupREP.-ALIGNED for Risch's campaign | 500 LV | 18 | 52 | R+34 | R+29.7 moved 4.3 toward I | 25% | source |
| Aug 4–7 | The Bullfinch GroupDEM.-ALIGNED for Achilles's campaign | 608 LV | 30 | 34 | R+4 | R+8.1 moved 4.1 toward R | 22% | source |
| Jul 28–30 | Change ResearchDEM.-ALIGNED for John Stegner, Independent candidate for governor | 1,213 LV | 21 | 43 | R+22 | R+25.1 moved 3.1 toward R | 22% | source |
| May 29 – Jun 1 | The Bullfinch GroupDEM.-ALIGNED for Achilles's campaign | 774 RV | 36 | 40 | R+4 | R+8.1 moved 4.1 toward R | 2.9% | source |
| Mar 16–17 | Public Policy PollingDEM.-ALIGNED for Achilles's campaign | 639 RV | 34 | 48 | R+14 | R+17.5 moved 3.5 toward R | 3.2% | source |
LV: likely voters. RV: registered voters. A: all adults. “Adjusted” is the published margin after removing the sponsor shift and the pollster’s measured house effect; the small print says how far that moved the poll. Dem.-aligned and Rep.-aligned mark polls paid for by a party, a campaign, or an allied group, or taken by a firm whose published work is mostly for one side. They are shifted by the average lean of such polls, then counted at full weight.
Recent results for this office
| Year | Democrat | Republican | Result |
|---|---|---|---|
| 2022 | David Roth | Mike Crapo | R+31.9 |
| 2020 | Paulette E. Jordan | James E. Risch | R+29.4 |
| 2016 | Jerry Sturgill | Mike Crapo | R+38.4 |
| 2014 | Nels Mitchell | James E. Risch | R+30.7 |