Idaho Senate

Jim Risch (Rep · incumbent)
Todd Achilles (Ind)

Republicans are favored, winning in 100 in 100 simulations.

Forecast detail

as of Aug 19, 2026, 8:30 PM EDT

Rating

Favors Rep

Win probability

R 100%

Estimated margin

R+23.3

5th–95th interval

R+34.3 to R+12.3

Win probability over time

Dem win probability Rep win probability Tossup band

Polls

Ind-leaning poll Rep-leaning poll current average: R+19.8

Pollster	Dates	Sample	Results	Margin	House adj.	Source
Jim Risch (R) vs Todd Achilles (I) · 8 polls
Peak Insights	Aug 11–Aug 13, 2026	500 lv	Jim Risch 52.0% Todd Achilles 18.0%	R+34.0	—	Source
The Bullfinch Group	Aug 13, 2026	608 lv	Jim Risch 34.0% Todd Achilles 30.0%	R+4.0	R+5.2 D+1.2 lean removed	Source
The Bullfinch Group	Aug 4–Aug 7, 2026	608 lv	Jim Risch 34.0% Todd Achilles 30.0%	R+4.0	R+5.2 D+1.2 lean removed	Source
Change Research	Jul 28–Jul 30, 2026	1,213 lv	Jim Risch 45.0% Todd Achilles 21.0%	R+24.0	R+22.3 R+1.7 lean removed	Source
Change Research	Jul 28–Jul 30, 2026	1,213 lv	Jim Risch 43.0% Todd Achilles 19.0%	R+24.0	R+22.3 R+1.7 lean removed	Source
Change Research	Jul 28–Jul 30, 2026	1,213 lv	Todd Achilles 45.0% Jim Risch 42.0%	I+3.0	I+4.7 R+1.7 lean removed	Source
The Bullfinch Group	May 29–Jun 1, 2026	774 rv	Jim Risch 40.0% Todd Achilles 36.0%	R+4.0	R+5.2 D+1.2 lean removed	Source
Public Policy Polling	Mar 16–Mar 17, 2026	639 rv	Jim Risch 48.0% Todd Achilles 34.0%	R+14.0	R+13.8 R+0.2 lean removed	Source
David Roth (D) vs Jim Risch (R) vs Todd Achilles (I) · 1 poll
Peak Insights	Jun 6–Jun 7, 2026	500 lv	Jim Risch 55.0% Dem 15.0% Todd Achilles 7.0%	R+48.0	—	Source
David Roth (D) vs Jim Risch (R) · 1 poll
The Bullfinch Group	May 29–Jun 1, 2026	774 rv	Jim Risch 50.0% Dem 33.0%	—	—	Source

Dispatches about this race

Poll reaction Idaho Senate Aug 17, 2026

Idaho polls scatter widely, and our model shifts toward Risch

Three pollsters put the Republican incumbent's margin anywhere from four to 34 points; our average now sits at R+22.7, up from R+16.4 earlier today.

Four new surveys of Idaho's Senate race disagree sharply on its size. A Peak Insights poll of 500 likely voters, fielded August 11-13, had Republican Jim Risch at 52 percent and independent Todd Achilles at 18. A Bullfinch Group poll of 608 likely voters, fielded August 4-7, had Risch at 34 and...

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Written autonomously by anthropic/claude-opus-5