**Two Republican Senate incumbents have already lost renomination this cycle—Bill Cassidy in Louisiana and John Cornyn in Texas—both defeated by challengers aligned with stronger Trump support amid intraparty tensions.** Cassidy fell in a May primary and runoff after criticism over his impeachment vote and health policy stances; Cornyn lost his May runoff following a late endorsement shift to Ken Paxton. With additional Republican primaries still scheduled into August and beyond, trader consensus at 74% for exactly three losses reflects the view that one more upset remains probable given the pattern of challenges targeting perceived moderates or holdouts. Outcomes of two or four sit further back, consistent with historical low rates of Senate primary defeats but elevated this cycle by factional dynamics and endorsement influence. No other confirmed losses have occurred as of mid-August.
Experimental AI-generated summary referencing Polymarket data. This is not trading advice and plays no role in how this market resolves. · Updated3 74.0%
4 13.2%
2 9.3%
>4 5.2%
$54,091 Vol.
$54,091 Vol.
0
<1%
1
<1%
2
9%
3
74%
4
13%
>4
5%
3 74.0%
4 13.2%
2 9.3%
>4 5.2%
$54,091 Vol.
$54,091 Vol.
0
<1%
1
<1%
2
9%
3
74%
4
13%
>4
5%
This market will resolve according to the number of Republican Senate incumbents who do not win their nominating election to move on to the general election as a result of the 2026 midterm primary elections.
An incumbent will be considered not to have won their election if they are not declared the winner of the election they sought, including if they withdraw, suspend, or otherwise leave the race at any point after officially registering as a candidate, regardless of the reason. Incumbents who do not officially register as candidates for reelection will not be considered.
This market will resolve based on the results of all Senate nominating elections, including party primaries, top-two or jungle primaries, and primaries for special elections, that are scheduled to occur between March 1 and September 30, 2026. If a required runoff for any such election or a subsequent qualifying round in a non-partisan primary system could change the market’s outcome, the market will remain open until that contest is conclusively called by this market’s resolution sources.
A candidate's party will be determined by their ballot-listed or otherwise identifiable affiliation with that party at the time of their nominating election. A candidate without a ballot-listed affiliation to either the Democratic or Republican parties will be considered a member of one of these parties based on the party with which they most recently expressed their intent to caucus prior to the conclusion of the relevant nominating election.
The resolution source for this market will be the Associated Press, Fox News, and NBC. This market will resolve once all three sources have conclusively called all relevant nominating elections. If all three sources do not achieve consensus in calling the relevant races for this market, it will resolve based on official state certification of the nominating election results.
Market Opened: Jan 14, 2026, 2:51 PM ET
Resolver
0x2F5e3684c...This market will resolve according to the number of Republican Senate incumbents who do not win their nominating election to move on to the general election as a result of the 2026 midterm primary elections.
An incumbent will be considered not to have won their election if they are not declared the winner of the election they sought, including if they withdraw, suspend, or otherwise leave the race at any point after officially registering as a candidate, regardless of the reason. Incumbents who do not officially register as candidates for reelection will not be considered.
This market will resolve based on the results of all Senate nominating elections, including party primaries, top-two or jungle primaries, and primaries for special elections, that are scheduled to occur between March 1 and September 30, 2026. If a required runoff for any such election or a subsequent qualifying round in a non-partisan primary system could change the market’s outcome, the market will remain open until that contest is conclusively called by this market’s resolution sources.
A candidate's party will be determined by their ballot-listed or otherwise identifiable affiliation with that party at the time of their nominating election. A candidate without a ballot-listed affiliation to either the Democratic or Republican parties will be considered a member of one of these parties based on the party with which they most recently expressed their intent to caucus prior to the conclusion of the relevant nominating election.
The resolution source for this market will be the Associated Press, Fox News, and NBC. This market will resolve once all three sources have conclusively called all relevant nominating elections. If all three sources do not achieve consensus in calling the relevant races for this market, it will resolve based on official state certification of the nominating election results.
Resolver
0x2F5e3684c...**Two Republican Senate incumbents have already lost renomination this cycle—Bill Cassidy in Louisiana and John Cornyn in Texas—both defeated by challengers aligned with stronger Trump support amid intraparty tensions.** Cassidy fell in a May primary and runoff after criticism over his impeachment vote and health policy stances; Cornyn lost his May runoff following a late endorsement shift to Ken Paxton. With additional Republican primaries still scheduled into August and beyond, trader consensus at 74% for exactly three losses reflects the view that one more upset remains probable given the pattern of challenges targeting perceived moderates or holdouts. Outcomes of two or four sit further back, consistent with historical low rates of Senate primary defeats but elevated this cycle by factional dynamics and endorsement influence. No other confirmed losses have occurred as of mid-August.
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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