BATTLE FOR THE SENATE: New Hampshire Votes as Trump-Backed Sununu Faces Brown, Socialist Challenger Threatens Democrat Establishment

MANCHESTER, N.H. — New Hampshire voters are preparing to deliver one of the most consequential verdicts of the 2026 primary season Tuesday, with an open U.S. Senate seat potentially determining whether Republicans preserve their majority or Democrats find a path back to control of the chamber.

At the center of the Republican contest are two familiar political heavyweights: former Sens. John E. Sununu and Scott Brown.

Sununu enters the final hours as the Republican frontrunner, carrying President Donald Trump’s endorsement and a substantial fundraising advantage over Brown. Trump’s decision to back Sununu was notable given past friction between the president and members of the Sununu political family, but national Republicans have increasingly consolidated behind the former senator.

Brown, meanwhile, is attempting another political comeback.

The former Massachusetts senator stunned the political establishment in 2010 when he captured the Senate seat previously held by the late Ted Kennedy. Brown later moved to New Hampshire and unsuccessfully challenged Democratic Sen. Jeanne Shaheen in 2014. Twelve years later, he is again seeking a path to Washington.

But polling suggests Brown faces a steep climb.

A recent Saint Anselm College survey reported by NHJournal showed Sununu leading Brown 54% to 24% among Republican primary voters. Sununu has also argued that his campaign is already looking toward November, while Brown has accused his opponent of avoiding scrutiny after Sununu declined to participate in a planned WMUR primary debate.

The winner will immediately inherit one of the Republican Party’s biggest opportunities to flip a Democratic-held Senate seat.

Shaheen, the three-term Democratic incumbent and former New Hampshire governor, is retiring rather than seeking another term. Republicans currently hold a 53-47 Senate majority, meaning Democrats need a net gain of four seats to seize outright control while a Republican administration remains in the White House.

That arithmetic makes New Hampshire dangerous territory for Democrats.

Pappas Faces Challenge From His Left

On the Democratic side, four-term Rep. Chris Pappas is favored against scientist and democratic socialist Karishma Manzur, but what once appeared to be an easy nomination has attracted greater attention as Manzur gained ground among progressive voters.

Pappas has the backing of much of the Democratic establishment, including retiring Sen. Shaheen and former Vice President Kamala Harris, and holds a major fundraising advantage.

Manzur, however, is campaigning as an unapologetic challenge to the Democratic establishment.

During the campaign she has attacked Pappas from the left over healthcare, Israel and campaign donations, presenting herself as an alternative to what she calls corporate Democratic politics.

The two clashed during their final televised debate September 4, with Pappas emphasizing his congressional record while Manzur pushed a considerably more progressive platform.

Recent polling shows why Democrats cannot completely dismiss the challenge.

An August University of New Hampshire Survey Center poll showed Pappas ahead of Manzur 47% to 34%, a dramatic tightening from April, when the same survey had Pappas leading 61% to 18%. Other surveys have shown a considerably larger Pappas advantage, meaning the exact size of Manzur’s support remains uncertain.

For conservatives, Manzur’s rise provides another example of the growing influence of openly socialist politics inside Democratic primaries.

For Democrats, the immediate concern is more practical: avoiding a bruising ideological fight while trying to defend a Senate seat that could become decisive in November.

New Hampshire Suddenly Looks Competitive

The general-election picture is anything but settled.

One recent UNH survey found Sununu narrowly leading Pappas 45% to 43%, suggesting Republicans could have a realistic opportunity to capture the seat.

But another recent Saint Anselm survey found the opposite result, showing Pappas ahead of Sununu by seven points. The conflicting numbers underline New Hampshire’s unpredictable political character rather than establishing a clear November favorite.

Pappas himself has acknowledged the danger.

He recently described New Hampshire as a “purple state” and warned that Democrats cannot afford to lose seats they already hold while simultaneously attempting to gain the four seats necessary to capture the Senate.

Republicans see an opening.

New Hampshire has voted Democratic in recent presidential elections, but Republicans remain highly competitive at the state level. GOP Gov. Kelly Ayotte previously represented the state in the U.S. Senate, and Republicans hope an experienced nominee such as Sununu can rebuild the coalition necessary to break Democrats’ grip on the state's federal delegation.

Trump’s Endorsement Faces a Test

Tuesday will also provide another measurement of Trump’s influence over Republican voters.

His endorsement of Sununu placed the president firmly on one side of a contest between two candidates who have both served in the Senate and who broadly agree on many conservative policy priorities.

Unlike insurgent-versus-establishment Republican primaries elsewhere, the New Hampshire battle has largely been a contest over electability, experience and which former senator is best positioned to defeat Pappas.

Sununu has largely run as the frontrunner.

Brown has tried to turn that confidence against him, criticizing Sununu for skipping the WMUR debate and arguing New Hampshire voters deserve more direct scrutiny of the presumed favorite. Sununu has responded that the candidates have already appeared together repeatedly and that he preferred spending the closing stretch campaigning directly with voters.

Now voters decide.

Polls begin opening across New Hampshire Tuesday morning, September 8, with closing times varying by municipality between approximately 7 p.m. and 8 p.m. Eastern Time.

The winners will have only 56 days before the November 3 general election.

For Republicans, New Hampshire represents an opportunity to turn a Democratic retirement into another Senate seat and strengthen their majority.

For Democrats, losing it could make their already difficult road back to Senate control dramatically harder.

And if the latest polling is any indication, the Granite State may be preparing to become one of the fiercest battlegrounds in America.