Trump backs former critic Sununu in high-stakes swing state Senate race

President Donald Trump on Sunday endorsed former Sen. John E. Sununu of New Hampshire, a longtime GOP Trump critic, over one of his first-term ambassadors, former Sen. Scott Brown, in a crucial Senate race that's one of a handful that may determine the Senate majority in the midterm elections.

Sununu, who was praised by Trump as an "America First Patriot" who "will work tirelessly to advance our America First Agenda," is seen by top Senate Republicans as the strongest candidate to flip the seat held by longtime Democratic Sen. Jeanne Shaheen, who is retiring at the end of this year rather than seek re-election to a fourth six-year term.

"John E. Sununu has my Complete and Total Endorsement — HE WILL NOT LET YOU DOWN. MAKE AMERICA GREAT AGAIN — ELECT JOHN E. SUNUNU," Trump emphasized, in a post on social media.

Sununu is a former three-term representative who defeated then-Gov. Shaheen in New Hampshire's 2002 Senate election. But the senator lost to Shaheen in their 2008 rematch.

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"I want to thank the President for his support and thank the thousands of Granite Staters who are supporting me," Sununu said after landing Trump's endorsement.

The endorsement will further boost Sununu, who enjoys a polling and fundraising advantage over Brown.

After Trump's endorsement, the Senate Leadership Fund, which is aligned with Senate Majority Leader John Thune, said on X that "John Sununu is the clear choice to be New Hampshire's next US Senator, and President Trump's critical endorsement has put an end to the primary."

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But Brown, as of now, has no intentions of dropping out.

"I’ve always believed that the people of New Hampshire are the ultimate authority on our future, and they deserve a choice between candidates seeking to earn their support," he said in a statement.

And apparently questioning Sununu's MAGA credentials, he added, "I am running to ensure our America First agenda is led by someone who views this mission not as a career path, but as a continuation of a lifelong commitment to service."

Brown emphasized, "My priorities for New Hampshire remain clear: a stronger economy, a secure border, reliable and affordable energy and better health care for our veterans. This mission has always been about you, not me. Let’s keep working!"

Sununu is a brand name in New Hampshire politics. His father, John H. Sununu, is a former governor who later served as chief of staff in then-President George H.W. Bush's White House. And one of his younger brothers is former Gov. Chris Sununu, who won election and re-election to four two-year terms steering the Granite State.

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But Sununu has a long history of backing Trump rivals. He served as national co-chair on the 2016 Republican presidential campaign of then-Ohio Gov. John Kasich, who declined to support Trump as the party's nominee.

And Sununu, along with then-Gov. Chris Sununu, endorsed former ambassador and former South Carolina Gov. Nikki Haley in the 2024 New Hampshire Republican presidential primary, as she battled Trump for the nomination. 

And on the eve of the first-in-the-nation presidential primary, the former senator wrote an opinion piece titled "Donald Trump is a loser," that ran in the New Hampshire Union Leader, the state's largest daily newspaper.

Brown endorsed Trump ahead of his 2016 New Hampshire primary victory, which launched him toward the GOP presidential nomination and ultimately the White House. Brown later served as U.S. ambassador to New Zealand during Trump's first term.

Some in New Hampshire's MAGA base immediately rejected the president's endorsement of Sununu, calling it a "slap in the face to grassroots supporters" who have long backed Trump.

"The Sununu family openly mocked, degraded, and worked against the America First movement, the President himself, and the policies that energized New Hampshire voters," a group of MAGA activists posted on X. "We will continue and intensify our campaign opposition to the Sununu operation."

Brown formally launched his Senate campaign in June, after over six months of reaching out to grassroots supporters in the state. He raised roughly $1 million during his first three months as a candidate.

Sununu jumped into the race in late October, with the backing of the National Republican Senatorial Committee (NRSC), which is the Senate GOP's campaign arm.

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NRSC chair Sen. Tim Scott said at the time that Senate Republicans were "all-in" for Sununu.

Since then, Sununu has landed the backing of a majority of the Republicans in the Senate, as well as from GOP leaders in New Hampshire.

The seat in New Hampshire, along with an open Democrat-held seat in Michigan are two of the NRSC's top targets this year as they aim to expand their 53-47 majority in the chamber. Georgia, where the GOP views Democratic Sen. Jon Ossoff as very vulnerable, is the NRSC's other top target.

Sununu more than doubled Brown's fundraising haul during the past three months, and the latest public opinion polls in New Hampshire indicate Sununu with a double-digit lead over Brown in the GOP primary, which won't be held until September.

Pappas, a four-term congressman who represents the eastern half of the state, outraised both Sununu and Brown combined during the 4th quarter of 2025 fundraising.

And the latest polls indicate Pappas topping Sununu by single digits and Brown by double digits in hypothetical general election matchups.

Pappas is the clear front-runner for his party's nomination, in a race that also includes Karishma Manzur, a member of the New Hampshire Democratic Party's rules committee.