NH Senator Shaheen throws a wrench in Democrats’ plans to control the Senate; refuses to run in 2026

New Hampshire Democratic Sen. Jeanne Shaheen announced on Wednesday that she is not running for a fourth term in 2026, saying “it is just time.” “There are urgent challenges, both here at home and around the world,” Shaheen, the ranking member of the Foreign Relations Committee, said.

Shaheen’s retirement deprives the Democrats of having the incumbency advantage in the 2026 New Hampshire Senate race. Incumbency is a huge advantage, and has allowed Democrats to win re-election in Republican leaning states, and Republicans to win re-election in Democratic leaning states.

If Chris Sununu, a moderate Republican, who won 4 straight gubernatorial elections in New Hampshire, runs for the 2026 Senate seat, he would have a legitimate chance to add to the GOP’s Senate majority.

The Democrats are already in a position where, barring a miracle, the earliest they could take back the Senate majority is 2028, and even that is unlikely. If Democrats lose a Senate seat in New Hampshire, it will just make the climb back to a majority even more difficult.

The GOP currently has 53 Senate seats. But that comes with Republicans holding only 4 of the 14 possible Senate seats from the widely agreed upon 7 swing states of the 2024 election. Put another way, if the GOP and the Democrats evenly split the 7 true battleground states (all of which were won by Trump in 2024), they would have 56 Senate seats.

You could subtract Maine Republican Senator Susan Collins’ seat and make that 55 seats (although it seems likely that Ms Collins will win re-election again in 2026 and thus keep a Maine Senate seat Republican until at least 2032).

But then, the baseline is, if all comfortable Republican and Democratic states have their Senate seats go to their respective parties, then a 50-50 split of the competitive states gives the GOP a base of 55 seats. Theoretically, that would mean a clean swap of all 14 competitive state Senate seats gives the GOP 62 Senate seats, and the Democrats only 52.

That means that if the GOP were to gain a seat in Democratic leaning New Hampshire, the Democrats would have to win multiple Senate races in Republican leaning states to win a Senate majority any time in the future.

Now of course, just because incumbent Democratic Senator Shaheen is not seeking re-election, and popular former Republican governor Sununu might run for the Senate seat, does not make that seat lean or even tilt Republican. It just provides a possible opportunity for the GOP to further expand their Senate majority, and creates another headache for Senate Democrats.

With the Democratic Party on the back foot and experiencing an identity crisis, the possible opening the GOP is getting to further expand its majority long term is not something anyone on the political left will welcome.