2026 Senate map: GOP starts with 53–47 edge as 35 seats, including Ohio and Florida specials, go to voters

Republicans head into the 2026 midterms with a 53–47 majority in the U.S. Senate, a tally that counts the two independents who caucus with the Democrats. Control of the chamber will be tested as 35 seats go before voters, including two high-profile special elections.

Two of those contests will permanently fill seats vacated for administration posts: the Ohio seat left by JD Vance when he became vice president and the Florida seat Marco Rubio vacated to serve as secretary of state. Beyond those vacancies, the cycle features significant turnover.

Nine senators are retiring — five Republicans and four Democrats — contributing to 11 open seats overall. In terms of incumbency, Democrats are defending nine seats they currently hold, while Republicans are defending 15. The path back to the majority is steep for Democrats.

To retake the Senate, they must keep all of their current seats and flip four that are Republican-held — a difficult task even though the party out of power typically gains ground in midterms. With dozens of races on the ballot and multiple open seats, both parties face a sprawling map.

The balance of power will hinge on whether Democrats can protect their defenses while notching four pickups against a Republican majority that begins the cycle with the advantage.