Full Breakdown
New Hampshire Senate Primaries: Open Seat Becomes Battleground for Senate Control
9/9/2026, 1:54:11 AM
Core Event
On September 8, 2026, New Hampshire voters will choose party nominees for the U.S. Senate seat being vacated by retiring Democrat Sen. Jeanne Shaheen. The Democratic primary pits Rep. Chris Pappas against medical scientist Karishma Manzur. The Republican primary features former state senator John E. Sununu, endorsed by President Donald Trump, and former Massachusetts senator Scott Brown. The winners will meet in the November 3 general election, a race that could affect the Senate’s 53-47 Republican edge.
Background & Context
Shaheen’s retirement opened the only open Senate seat in New England this cycle, making New Hampshire a focal point. Republicans have not won a Senate race in the state since 2010, while the governorship and legislature are currently Republican-controlled. Democrats need four net gains to retake the chamber, so the Shaheen seat is a “must-keep” race.
Timeline
- August 26, 2026 – UNH poll: Pappas leads Manzur 47 % to 34 %.
- June 30, 2026 – Americans for Prosperity Action reports $3.3 million spent supporting Sununu and opposing Pappas.
- September 8, 2026 – Primary voting (polls close 7-8 p.m. ET).
Data & Statistics
- Fundraising: Pappas has $4.3 million cash on hand; Sununu $4.1 million; Brown $2.2 million (FEC).
- Polls: UNH poll (Aug 26) shows Sununu 40 points ahead of Brown; Saint Anselm poll (early Sept.) shows a 30-point lead.
- Super-PAC spending: Americans for Prosperity Action has contributed at least $3.3 million since June 30.
Why It Matters / Impact
A Sununu win would add to the GOP’s 53-47 majority, lowering the number of seats Democrats must flip. A Pappas victory would keep the Senate balance unchanged. The contest also highlights the influence of Trump endorsements in GOP primaries and the rise of progressive challengers within the Democratic Party.
Official Statements & Responses
- President Donald Trump endorsed Sununu in February.
- Sen. John Thune and the National Republican Senatorial Committee backed Sununu.
- Pappas cited endorsements from former Vice President Kamala Harris, Sen. Shaheen, and Sen. Maggie Hassan, emphasizing his anti-corruption platform.
On-the-Ground Reports
Voters in Berlin and Coos County expressed mixed feelings: some see Sununu’s family legacy as an asset, others note confusion over the name after recent media misidentifications.
Conflicting Reports & Gaps
- Poll margins differ: UNH shows a 40-point Sununu lead over Brown; Saint Anselm shows a 30-point lead. Discrepancies are attributed to sample size and timing.
- Fundraising totals for Sununu vary slightly between filings, with figures of $4.1 million and $4.0 million reported. Final cash-on-hand numbers await final FEC confirmation.
Verbatim Quotes
- “I’m the only truly independent candidate here who can actually vote on anything with a clear conscience and with New Hampshire’s best interests at heart,” — Scott Brown
- “This is the kind of place where you can’t just run a bunch of TV ads and expect to win,” — Rep. Chris Pappas
- “One has a ‘D’ after their name. One has an ‘R’ after their name … neither of them have been able to address the real needs of the people,” — Karishma Manzur
What’s Next
- Primary results will be reported on the night of September 8 by the Associated Press.
- The general election is set for November 3, 2026.
- A state law change will move New Hampshire’s future primaries to June beginning in 2028, shortening the window between nomination and the general election.
