**Two confirmed primary defeats—Bill Cassidy in Louisiana and John Cornyn in Texas—have established a baseline of losses, with trader consensus centering on a total of three.** This positioning reflects the limited number of competitive Republican Senate primary challenges across the 2026 cycle, where most incumbents such as Tom Cotton, Jim Risch, and Roger Marshall face minimal opposition or have already advanced. Expectations for exactly one additional upset align with the current field of remaining contests and historical rates of Senate incumbent primary defeats, which stay low without widespread scandals or major realignments in voter priorities. Markets assign very low probability to zero or one loss overall, or to four or more, consistent with the modest scale of viable challenges observed so far.
Experimental AI-generated summary referencing Polymarket data. This is not trading advice and plays no role in how this market resolves. · Updated3 71.6%
4 15.8%
2 7.1%
>4 <1%
$59,335 Vol.
$59,335 Vol.
0
<1%
1
<1%
2
7%
3
72%
4
16%
>4
<1%
3 71.6%
4 15.8%
2 7.1%
>4 <1%
$59,335 Vol.
$59,335 Vol.
0
$4,221 Vol.
<1%
1
$3,323 Vol.
<1%
2
$31,338 Vol.
7%
3
$10,835 Vol.
72%
4
$5,524 Vol.
16%
>4
$4,094 Vol.
<1%
The 2026 midterm elections are scheduled to be held on November 3, 2026, with congressional primaries running from March through September.
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.**Two confirmed primary defeats—Bill Cassidy in Louisiana and John Cornyn in Texas—have established a baseline of losses, with trader consensus centering on a total of three.**
This positioning reflects the limited number of competitive Republican Senate primary challenges across the 2026 cycle, where most incumbents such as Tom Cotton, Jim Risch, and Roger Marshall face minimal opposition or have already advanced. Expectations for exactly one additional upset align with the current field of remaining contests and historical rates of Senate incumbent primary defeats, which stay low without widespread scandals or major realignments in voter priorities. Markets assign very low probability to zero or one loss overall, or to four or more, consistent with the modest scale of viable challenges observed so far.
The 2026 midterm elections are scheduled to be held on November 3, 2026, with congressional primaries running from March through September.
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.
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
Volume
$59,335Market Opened
Jan 14, 2026, 2:51 PM ETResolver
0x2F5e3684c...Outcome proposed: No
No dispute
Final outcome: No
The 2026 midterm elections are scheduled to be held on November 3, 2026, with congressional primaries running from March through September.
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.**Two confirmed primary defeats—Bill Cassidy in Louisiana and John Cornyn in Texas—have established a baseline of losses, with trader consensus centering on a total of three.**
This positioning reflects the limited number of competitive Republican Senate primary challenges across the 2026 cycle, where most incumbents such as Tom Cotton, Jim Risch, and Roger Marshall face minimal opposition or have already advanced. Expectations for exactly one additional upset align with the current field of remaining contests and historical rates of Senate incumbent primary defeats, which stay low without widespread scandals or major realignments in voter priorities. Markets assign very low probability to zero or one loss overall, or to four or more, consistent with the modest scale of viable challenges observed so far.
The 2026 midterm elections are scheduled to be held on November 3, 2026, with congressional primaries running from March through September.
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.
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.
Volume
$59,335Market Opened
Jan 14, 2026, 2:51 PM ETResolver
0x2F5e3684c...Outcome proposed: No
No dispute
Final outcome: No
**Two confirmed primary defeats—Bill Cassidy in Louisiana and John Cornyn in Texas—have established a baseline of losses, with trader consensus centering on a total of three.** This positioning reflects the limited number of competitive Republican Senate primary challenges across the 2026 cycle, where most incumbents such as Tom Cotton, Jim Risch, and Roger Marshall face minimal opposition or have already advanced. Expectations for exactly one additional upset align with the current field of remaining contests and historical rates of Senate incumbent primary defeats, which stay low without widespread scandals or major realignments in voter priorities. Markets assign very low probability to zero or one loss overall, or to four or more, consistent with the modest scale of viable challenges observed so far.
Experimental AI-generated summary referencing Polymarket data. This is not trading advice and plays no role in how this market resolves. · UpdatedRelated
Will Democratic Senate incumbents win all their nominating elections in the 2026 cycle?
93%
Will Republican House incumbents not win in between four and six nominating elections in the 2026 cycle?
94%
Will Democratic House incumbents not win in between ten and twelve nominating elections in the 2026 cycle?
75%
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Frequently Asked Questions