Which party will control the US Senate after the 2026 midterms?

Custom

Market Odds

Select an outcome to show or hide its line on the chart.

Democratic Party65.5%
Republican Party34.5%
Powered by PolymarketLive: odds update automatically

News

Trump endorses Darline Graham in 2026 South Carolina Senate race

Trump’s endorsement may bolster Graham’s campaign by reinforcing her Republican ties, but its impact is limited by its niche platform origin.

By ESTEFANO GOMEZ

Obama to campaign with El-Sayed in Michigan Senate race this month

Obama’s support for El-Sayed could boost Democratic momentum in Michigan, potentially influencing voter turnout and market perceptions.

By ESTEFANO GOMEZ

Trump backs Ricketts in tight Nebraska Senate race amid beef import backlash

Trump’s support in Nebraska may reshape traditional party dynamics, highlighting the potential influence of independent candidates amid local discontent.

By ESTEFANO GOMEZ

Kansas Senate race tightens as Democrats target rural discontent with Trump policies

The tightening Kansas Senate race signals potential shifts in traditionally Republican areas, reflecting broader political realignments.

By ESTEFANO GOMEZ

Sununu gains ground in competitive New Hampshire Senate race against Pappas

The competitive Senate race in New Hampshire could influence party strategies and voter engagement, impacting broader political dynamics.

By ESTEFANO GOMEZ

Trump to hold Texas rally as GOP fights to retain key seats in 2026 elections

Trump’s rally could shift voter sentiment, impacting GOP’s strategy and market expectations in the competitive 2026 Texas elections.

By ESTEFANO GOMEZ

Winklevoss twins spend over $2.9 million in a day to shape Ohio Senate race

The influx of crypto-backed funding in Ohio’s Senate race highlights the growing influence of digital currency interests in U.S. politics.

By JOHN CHEN

Iowa’s rising cancer rates central to Senate race as midterms approach

The focus on healthcare and pollution in Iowa’s Senate race may shift voter priorities, impacting election outcomes and market dynamics.

By ESTEFANO GOMEZ

No more articles for this market

Understanding this market

Senate control is a different question from who wins the most votes nationwide. This market concerns control of the chamber after the election. Read the contract rules for how tied seats, independents, special elections and runoffs count. A change in the chart shows a change in traded expectations; it does not establish that a particular news story caused the move.

How to read the probabilities

A Yes price of $0.60 is displayed as 60%. It represents the price traders assign to that contract paying out, not a survey of voters. Liquidity, spreads and trading activity can affect prices. Neither a high price nor a resolved-looking price proves the official outcome. Check the status and full source rules.

Resolution rules and source

Rules below come from Polymarket. Follow the source for updates and the final determination.

Will the Democratic Party control the Senate after the 2026 Midterm elections?
This market will resolve according to the party that wins control of the United States Senate in the 2026 United States midterm election. A party wins control of the United States Senate if it wins a majority of the chamber’s voting seats. If no party wins a majority of voting seats, the party that wins control of the chamber is the party that wins half of the voting seats and holds the Vice Presidency. If the outcome remains ambiguous after applying the above criteria, the chamber will be deemed controlled by the party with which the first selected President Pro Tempore of the Congress that convenes after the specified election is affiliated. The following rules govern the counting of seats for determining which party wins control of the chamber. All regular and special Senate elections that determine representation in the upcoming 120th Congress and are scheduled to take place in November 2026 as of October 31, 2026 are included. Runoffs for qualifying elections will determine attribution of the relevant seat, even if they take place after November 2026. Vacant seats for which no election or special election to fill the seat is scheduled to take place in November 2026 as of October 31, 2026 will be treated as held by the party affiliation of the most recent member to hold that seat. For seats contested in the specified election, seats are attributed to the party under which the member was elected. If a member-elect changes party affiliation, or vacates their seat, between election day and the formal organization of Congress, the seat is attributed to the party under which the member was elected. For seats not contested in the specified election, seats are attributed to the party that holds the seat as of the date of the election. If a current sitting member of the U.S. Senate who is not up for election changes party affiliation or vacates their seat after the date of the election, the seat is attributed to the party under which the member was affiliated at the time of the election. Senate members elected as independents who formally caucus with, or, for newly elected members, who announce their intent to caucus with, a party are included in that party’s count. If the caucus decisions of members of the Senate elected as independents cannot be determined on the date of the election, this market may remain open until the earlier of (i) an announcement from the relevant members of their intents to caucus, or (ii) January 4th, 11:59 PM ET of the following calendar year. If no such announcement is made by January 4th, 11:59 PM ET of the following calendar year, the member will not count towards the seat count of any party. The resolution sources for this market will be official information from relevant state electoral authorities, the United States Congress, and a consensus of credible reporting.

Resolution source: See the rules and the linked Polymarket event.

Will the Republican Party control the Senate after the 2026 Midterm elections?
This market will resolve according to the party that wins control of the United States Senate in the 2026 United States midterm election. A party wins control of the United States Senate if it wins a majority of the chamber’s voting seats. If no party wins a majority of voting seats, the party that wins control of the chamber is the party that wins half of the voting seats and holds the Vice Presidency. If the outcome remains ambiguous after applying the above criteria, the chamber will be deemed controlled by the party with which the first selected President Pro Tempore of the Congress that convenes after the specified election is affiliated. The following rules govern the counting of seats for determining which party wins control of the chamber. All regular and special Senate elections that determine representation in the upcoming 120th Congress and are scheduled to take place in November 2026 as of October 31, 2026 are included. Runoffs for qualifying elections will determine attribution of the relevant seat, even if they take place after November 2026. Vacant seats for which no election or special election to fill the seat is scheduled to take place in November 2026 as of October 31, 2026 will be treated as held by the party affiliation of the most recent member to hold that seat. For seats contested in the specified election, seats are attributed to the party under which the member was elected. If a member-elect changes party affiliation, or vacates their seat, between election day and the formal organization of Congress, the seat is attributed to the party under which the member was elected. For seats not contested in the specified election, seats are attributed to the party that holds the seat as of the date of the election. If a current sitting member of the U.S. Senate who is not up for election changes party affiliation or vacates their seat after the date of the election, the seat is attributed to the party under which the member was affiliated at the time of the election. Senate members elected as independents who formally caucus with, or, for newly elected members, who announce their intent to caucus with, a party are included in that party’s count. If the caucus decisions of members of the Senate elected as independents cannot be determined on the date of the election, this market may remain open until the earlier of (i) an announcement from the relevant members of their intents to caucus, or (ii) January 4th, 11:59 PM ET of the following calendar year. If no such announcement is made by January 4th, 11:59 PM ET of the following calendar year, the member will not count towards the seat count of any party. The resolution sources for this market will be official information from relevant state electoral authorities, the United States Congress, and a consensus of credible reporting.

Resolution source: See the rules and the linked Polymarket event.

All political markets