Incumbent Republican Jim Risch secured his party's nomination in the May 2026 primary with 67 percent of the vote, facing limited opposition and advancing to the general election against Democrat David Roth and independent Todd Achilles. Idaho's consistent Republican voting patterns in federal contests, combined with Risch's long tenure and the state's lack of competitive Democratic Senate victories in recent decades, underpin trader consensus around a 95.7 percent probability for a GOP winner. All major forecasters rate the seat as safe or solid Republican. Late developments that could alter outcomes remain limited to an unforeseen scandal, significant health event, or unusual independent momentum, though historical turnout and partisan margins make such shifts improbable before the November general election.
Experimental AI-generated summary referencing Polymarket data. This is not trading advice and plays no role in how this market resolves. · Updated$32,162 Vol.
$32,162 Vol.

Republican
96%

Democrat
3%
$32,162 Vol.
$32,162 Vol.

Republican
96%

Democrat
3%
A candidate shall be considered to represent a party in the event that he or she is the nominee of the party in question. Candidates other than the Democratic or Republican nominee (e.g., Greens, Libertarian, independent) may be added at a later date.
Candidates who run as independents will not be encompassed by the “Democrat” or “Republican” options regardless of any affiliation they may have with the party.
The resolution source for this market is the Associated Press, Fox News, and NBC. This market will resolve once all three sources call the race for the same candidate. If all three sources haven’t called the race in this state for the same candidate, this market will resolve based on the official certification.
Market Opened: Oct 13, 2025, 5:35 PM ET
Resolver
0x2F5e3684c...A candidate shall be considered to represent a party in the event that he or she is the nominee of the party in question. Candidates other than the Democratic or Republican nominee (e.g., Greens, Libertarian, independent) may be added at a later date.
Candidates who run as independents will not be encompassed by the “Democrat” or “Republican” options regardless of any affiliation they may have with the party.
The resolution source for this market is the Associated Press, Fox News, and NBC. This market will resolve once all three sources call the race for the same candidate. If all three sources haven’t called the race in this state for the same candidate, this market will resolve based on the official certification.
Resolver
0x2F5e3684c...Incumbent Republican Jim Risch secured his party's nomination in the May 2026 primary with 67 percent of the vote, facing limited opposition and advancing to the general election against Democrat David Roth and independent Todd Achilles. Idaho's consistent Republican voting patterns in federal contests, combined with Risch's long tenure and the state's lack of competitive Democratic Senate victories in recent decades, underpin trader consensus around a 95.7 percent probability for a GOP winner. All major forecasters rate the seat as safe or solid Republican. Late developments that could alter outcomes remain limited to an unforeseen scandal, significant health event, or unusual independent momentum, though historical turnout and partisan margins make such shifts improbable before the November general election.
Experimental AI-generated summary referencing Polymarket data. This is not trading advice and plays no role in how this market resolves. · Updated


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