Sept. 8, 2026, 8:00 PM EDT / Updated Sept. 8, 2026, 8:05 PM EDTBy Bridget Bowman

The battleground New Hampshire Senate race is set between Republican former Sen. John Sununu and Democratic Rep. Chris Pappas, NBC News projects, after both prevailed in their primaries Tuesday night.

Pappas defeated scientist Karishma Manzur, a member of the Democratic Socialists of America, in his primary, leading 62%-36% with about one-fifth of the vote counted. But it appears he could fall short of the support from primary voters that the Pappas campaign touted in recent internal polling.

The race could be key to the fight for the Senate majority in November. Republicans are confident that Sununu, a member of a well-known political family, can put the race in play. But Democrats dismiss GOP optimism in a state that President Donald Trump has never won.

Trump endorsed Sununu in the primary against former Massachusetts Sen. Scott Brown, who also served as an ambassador during Trump’s first term. Sununu had 70% support to Brown’s 25% with about a sixth of the vote counted.

First elected to the House in 2018, Pappas has long been viewed as the frontrunner in the race to replace retiring Democratic Sen. Jeanne Shaheen. And Pappas had already started to focus on the likely general election contest against Sununu, launching an attack against Sununu in mid-August.

“In Congress, Sununu gave huge tax breaks to pharma companies and sided with the insurance industry, and then he went to work for them and made $35 million,” Pappas said in the ad. “In Washington, I’m taking on this kind of corruption, refusing corporate PAC money and fighting to lower costs.”

Republicans, meanwhile, have already begun to attack Pappas. One Nation, the non-profit arm of the GOP super PAC Senate leadership fund, launched an ad knocking Pappas on taxes. The spot alleges the congressman “gave out tax breaks to New Yorkers for their million dollar homes” when he supported a sweeping climate and social safety net measure in 2021.

Trump’s approval rating is down and voters are raising concerns about the economy and the Iran war as the midterms approach. But Republicans are still optimistic with Sununu on the ballot in New Hampshire.

Sununu’s father and brother both served as governors of the state, and Sununu himself represented New Hampshire in the Senate from 2003 through 2008 after serving in the House.

He lost his bid for re-election in 2008 to Shaheen, who then served three terms before retiring this year.

Republicans believe they could have an opening with independent voters in the state who are averse to higher taxes, and they have GOP Gov. Kelly Ayotte on the ticket as she runs for a second two-year term. Ayotte is the last Republican to win a Senate race in New Hampshire, winning her first term in 2010 before losing re-election in 2016.

But Democrats dismiss Republicans’ optimism about New Hampshire.

Lauren French, a spokesperson for the Democratic super PAC Senate Majority PAC, acknowledged in a recent interview the New Hampshire race would be competitive, but said Democrats were confident they would prevail.

“New Hampshire feels like wish casting in a lot of ways,” French said of Republican optimism about the state. “We continue to put states that they didn’t even think were going to be competitive on the board, so they need to continue to assure donors, right, that they are also doing the same.”