What to know about Trump endorsement in U.S. Senate GOP primary in NH

Purple Heart returned to Seabrook family of WWII soldier
Congressman Chris Pappas presents a Purple Heart to the family of Pvt. Daniel E. Janvrin Jr., who was killed in action on November 12, 1944, during World War II.
- The Sununu family has long had a complicated relationship with Trump.
- Republicans are hoping to flip the Democratic seat held by retiring Sen. Jeanne Shaheen, D-N.H., in their quest to increase the GOP’s narrow majority in the U.S. Senate.
- It may be the desire to win the seat that led Trump to endorse Sununu instead of Brown, who has been more vocally supportive of the president.
Former Sen. John E. Sununu, R-New Hampshire, wrote an opinion piece for the Union Leader in 2024 titled “Donald Trump is a loser.” Yet in February, President Donald Trump endorsed him for U.S. Senate.
“John is strongly supported by the most Highly Respected Leaders in New Hampshire, and many Republicans in the U.S. Senate and, as your next Senator, he will work tirelessly to advance our America First Agenda,” Trump wrote on his social media platform.
The Sununu family has long had a complicated relationship with Trump: John E.’s father, former Republican Gov. John H. Sununu, called Trump a “loser all his life” during the 2016 presidential primary and his brother, former Republican Gov. Chris Sununu, supported former South Carolina Gov. Nikki Haley in her 2024 bid for president over Trump, but both later supported Trump during the general elections.
But Republicans are hoping to flip the Democratic seat held by retiring Sen. Jeanne Shaheen, D-New Hampshire, in their quest to increase the GOP’s narrow majority in the U.S. Senate, which now stands at 53-47. The seat is rated “Lean D” by the Cook Political Report. Sununu will be facing former Sen. Scott Brown, R-Massachusetts, in the Republican primary on Sept. 8.
It may be the desire to win the seat that led Trump to endorse Sununu instead of Brown, who has been more vocally supportive of the president.
“I suspect that this was a case in which Trump is looking for winners,” University of New Hampshire political science professor Dante Scala said. “He’s concerned about keeping Republican control of Congress for his last two years of his presidency, and I suspect that he, in that case, valued winning potential over loyalty.”
Why did Trump endorse Sununu?
Both Sununu and Brown are experienced candidates. Both have served in the Senate already and have similar records.
If Trump was endorsing by loyalty, Scala said, he should’ve endorsed Brown. Brown has often praised Trump’s policies and served as his ambassador to New Zealand during his first term as president, although he did criticize Trump in 2021 for the Jan. 6 insurrection.
Scala, along with other political scientists in New Hampshire, suspect that the party and Trump see Sununu has having the best chance of winning. The Sununus have long been popular in New Hampshire: John H. Sununu and Chris Sununu served three and four terms as governor respectively. Even before Trump endorsed, Sununu was leading Brown in the polls by double digits. He has also raised the most money: $3.6 million over Brown’s $1.9, according to FEC filings. And Sununu has won this seat before, defeating then-Gov. Jeanne Shaheen in 2002 to serve one term before Shaheen defeated him in 2008.
Despite their complicated relationship, “Trump respects the Sununu’s as winners in New Hampshire,” Scala said.
Scott, on the other hand, lost to Shaheen when he last ran for Senate in New Hampshire in 2014.
Trump also values winning potential in general, not just in this race. He has endorsed 313 candidates in Republican primaries around the country and has a near-perfect record: a 96% success rate in GOP contests across congressional, state legislative and statewide elections so far in 2026, according to a review of Trump’s picks by Ballotpedia. In a June 24 social media post, the president bragged about going “16-0” in primaries across multiple states on June 23.
“Trump’s pattern seems to be to endorse the candidate that’s most likely to win,” UNH Survey Center Director Andy Smith said. “So, I think that’s the case here.”
Can Brown win?
Just under two weeks out from the primary, Sununu seems poised to win. He leads Brown handily in two polls released this week: a University of New Hampshire Survey Center poll released Aug. 26 found him ahead 60% to 20%, and a Saint Anselm College Survey Center poll found him up 54% to 24%.
“As the UNH poll yesterday showed, John Sununu is well-positioned to win the primary, defeat Chris Pappas, and deliver results for the people of New Hampshire. Voters know John will be an independent voicein the Senate and always do what’s best for the state,” Sununu campaign spokesperson Mike Schrimpf said in response to a request for comment on how Trump’s endorsement will impact the race.
As in all elections, anything can happen, the political scientists said. But it’s an uphill battle for Scott. Even without the endorsement, Sununu had big advantages in name recognition and fundraising.
The Trump endorsement may have more of an impact had it been for Scott, Smith said, as it could’ve helped him counteract those strengths. Still, it’s a “big thumb on the scale,” Scala said.
Scott said in an email to Seacoastonline that he doesn’t think the endorsement will hurt him.
“John does not even have it on his website and never talks about it. Very strange,” he wrote. “We are working hard and a lot of the people that supported POTUS are supporting me. We will know soon.”