**Trader consensus around 600K–680K total votes reflects Idaho’s registered voter base of roughly 969K and expectations for a standard midterm Senate contest in a solidly Republican state.** With incumbent Jim Risch facing independent Todd Achilles after the Democratic nominee withdrew in July, the race lacks the intensity of a competitive partisan matchup, limiting mobilization on both sides. Historical patterns show Idaho general-election turnout at 43% in 2022 versus 64% in the 2024 presidential year, while the May 2026 primary drew only about 30%. Limited recent polling, minimal campaign spending contrasts, and the absence of high-profile coattails or ballot measures keep probabilities clustered in the mid-600K range, with modest separation possible only from late-cycle registration surges or unusually strong get-out-the-vote efforts by either campaign.