NEW HAMPSHIRE — Former U.S. Senators John Sununu and Scott Brown are the top candidates in the New Hampshire Republican primary for U.S. Senate, with Sununu holding a significant polling lead despite past friction with Donald Trump. The University of New Hampshire Survey Center found that Sununu maintained a strong lead, 60% to 20%, over Scott Brown in the primary, according to the UNH poll.

The New Hampshire Republican primary for an open U.S. Senate seat features eight candidates, including both former senators who previously held federal office. Jeanne Shaheen is retiring after serving three terms in the U.S. Senate, creating the vacancy that has drawn this field of contenders. The general election for the U.S. Senate in New Hampshire is eight weeks after the primary.

The New Hampshire Republican primary for U.S. Senate is scheduled for Tuesday, September 8, 2026. Donald Trump endorsed John Sununu for the U.S. Senate in February 2026, a move that came after Sununu called Trump a "loser" during the 2024 GOP presidential primary. Sununu served three terms in the U.S. House of Representatives and one term in the U.S. Senate before he was defeated by Democrat Jeanne Shaheen in the 2008 Senate election. As of September 2026, Sununu has not appeared on a ballot in 18 years.

Scott Brown won a special election to the U.S. Senate in Massachusetts in 2009 following the death of Senator Ted Kennedy. He lost his U.S. Senate seat in Massachusetts in 2012 and unsuccessfully challenged Jeanne Shaheen for the U.S. Senate in New Hampshire in 2014. Brown served as U.S. Ambassador to New Zealand and Samoa during Donald Trump's first term as president.

Confusion between John Sununu and his brother has persisted throughout the campaign cycle. Fox News misidentified John Sununu as his brother Chris Sununu in an October broadcast regarding his campaign announcement. A debate moderator introduced John Sununu as Chris Sununu in June 2026.

Chris Sununu served as governor of New Hampshire for eight years until 2025. John Sununu will turn 62 years old in the week of September 5, 2026, while Scott Brown will turn 67 years old in the same week.

Voters have expressed varied reasons for their support. Paul Martino, 57, of North Hampton, supports John Sununu. Ed Gleason, 89, of Pelham, supports Scott Brown.

Sununu addressed the confusion with his brother in an interview. "I’m sure when Chris ran, people thought he was me," Sununu said. "His independence and focus on New Hampshire is certainly something he got from me, and that I’ll try to emulate as well."

Brown criticized his opponent's connections to national political figures. "John can’t break with the president. He can’t break with all those special interests," Brown said.

He described his own approach differently. "I’m a freelancer. I have the ability to vote my conscience, because I read the bills. I see how they affect our state, country, debt and deficit and I vote, period." Brown also commented on voter recognition issues. "They say, ’Who’s John? The father’s running again?'" Brown said. "He’s not doing anything." He added, "I’m going to outwork him."

Sununu defended his record and future intentions without revisiting past conflicts. "I’m not going to review 20 years of political history," Sununu said. "I don’t need to worry about reelection. I don’t need to make anyone in Washington happy." He concluded, "I’ll just stand up for New Hampshire." On the Democratic side, Karishma Manzur and Chris Pappas are candidates in the New Hampshire Democratic primary for U.S. Senate.

Manzur is 52 years old and is a research scientist with a doctorate in biochemistry and molecular biology. Pappas is a four-term U.S. Representative who is 46 years old. Kamala Harris endorsed Chris Pappas for the U.S. Senate.