Senator Shaheen will not seek re-election next year after months of speculation that the 78-year-old, three-term lawmaker would step aside, making her the third Democrat to announce so far that he or she will not run in 2026. Ms. Shaheen’s departure, coupled with the retirements of other Democrats, could signal an admission that the party may be locked out of a Senate majority for years to come. 

In a video message to constituents released on Wednesday, Ms. Shaheen said she wanted to spend more time with her family rather than seek another six-year term. “I have made the difficult decision not to seek reelection in 2026. It’s just time,” she said. 

The likely Republican candidate for the seat, Scott Brown, served for nearly three years in the U.S. Senate representing Massachusetts before losing his re-election bid in 2012, only to then move to New Hampshire where he narrowly lost the 2014 Senate race to Ms. Shaheen. Mr. Brown met with Senate Republicans during their weekly lunch on Tuesday. 

The exodus of Democrats from the chamber next year speaks to lawmakers’ frustrations with being in the minority — a joyless position that septuagenarians are happy to avoid. If history and the polarization of states is any guide, it is likely that Democrats could be locked out of a Senate majority for at least the next six years. 

Ms. Shaheen is the third Democrat so far to announce his or her retirement. Senator Peters, at the age of just 66, said earlier this year that he will not run for a third term, which immediately made Michigan a top pick-up opportunity for Republicans next year. 

In a more stunning move, Senator Smith — who is only in her first full term and just turned 67 — said she, too, would leave the Senate in 2027. Ms. Smith said that she did not need to be the candidate next year given the “deep bench of political talent in Minnesota” that is “more than ready to pick up the work and carry us forward.”

Other Democrats are reportedly eyeing the exit, as well. The Colorado Sun reports that Senator Bennet — who once served as chief of staff to Senator Hickenlooper when he was in the governor’s mansion — is considering a run for governor in his home state next year, when Governor Polis will be term-limited out of office. If Mr. Bennet were to run and win that race, a Democrat would hold that seat until at least 2028. 

Senator Warner, who would be 72 at the start of another Senate term in January 2027, has yet to say if he will run for reelection next year. The only Republican to announce his retirement so far is Senator McConnell. 

Several Democrats’ decisions to flee Congress’s upper chamber could signal an acknowledgment that the party may be locked out of a Senate majority for years to come. In order to get to 51 seats next year, Democrats would have to run the table across states that President Trump won decisively in 2024. 

In their best case scenario, Democrats would have to defend their open seats in Michigan, Minnesota, and New Hampshire, while also reelecting Senator Ossoff. They would then have to Senator Collins’s seat in Maine — the only state Vice President Harris won last year which currently has a Republican senator. Even if they were to accomplish all of that, they would still have to beat three more GOP lawmakers in Trump won states like North Carolina, Texas, Ohio, or Iowa.