The stage for a pivotal U.S. Senate race was set Tuesday as New Hampshire primary voters selected their nominees. Democratic Representative Chris Pappas and former Republican Senator John E. Sununu will compete in November to succeed retiring Senator Jeanne Shaheen, a contest that leaders in both parties view as essential to determining which party controls the chamber.

With early returns showing Pappas holding 62% of the vote against Karishma Manzur’s 27% when 16% of precincts were counted, the outcome appeared decisive. Yet the margin masks a primary that was far more competitive than party insiders anticipated. Manzur, a scientist and progressive activist from Exeter, mounted a grassroots campaign built on sharp ideological contrasts. She logged 28,000 miles on her own campaign van, pushing for Medicare for All, a $25 federal minimum wage, higher taxes on the wealthy, and an end to U.S. support for Israel, which she accused of committing genocide in Gaza. Her most pointed attacks targeted Pappas’s long-standing ties to the American Israel Public Affairs Committee (AIPAC), which has poured hundreds of thousands of dollars into his campaigns over the years.

Pappas, who has represented New Hampshire’s First Congressional District for four terms and previously served as a state representative, Hillsborough County treasurer, and executive councilor, ran as a pragmatic reformer. His campaign emphasized experience and bipartisanship, echoing the styles of popular state Democrats like Shaheen and Senator Maggie Hassan. He finished his primary push with appearances alongside Senators Elizabeth Warren of Massachusetts and Mark Kelly of Arizona, underscoring strong support from national party figures. His family’s ownership of the Puritan Backroom restaurant in Manchester cemented his local ties, giving him familiar face value that Manzur could not match. Despite the final margin, Manzur’s ability to tap into dissatisfaction with establishment politics signaled a persistent ideological divide within the Democratic base.

On the Republican side, Sununu cruised to a commanding victory, securing 70% of the vote against Scott Brown’s 25% in early tallies. Both men are former senators, but the contest was never truly competitive. Sununu’s political brand is deeply rooted in New Hampshire: his brother, Chris Sununu, served as governor, and his father, John H. Sununu, also held the office. This legacy, combined with an early endorsement from President Donald Trump, effectively sealed the outcome. Sununu had once been a vocal Trump critic, but after the endorsement, he largely sidestepped discussing the president, offering only muted criticism on issues like the Iran conflict and tariff policies. Instead, he focused fire on Pappas, accusing him of voting in lockstep with Democratic leadership and supporting higher taxes.

Brown, who represented Massachusetts in the Senate from 2010 to 2012 before moving to New Hampshire for an unsuccessful 2014 Senate bid, stressed his independence but could not overcome Sununu’s advantages in name recognition and fundraising. Without Trump’s backing, Brown’s campaign struggled to gain traction.

Now the race moves to a general election that both parties see as a must-win in the fight for Senate control. The race offers voters a stark choice: Pappas champions pragmatic progressive policies and federal investment, while Sununu advocates for lower taxes and a more restrained government. Turnout in suburban and independent-leaning precincts will likely decide the outcome. The retirement of Shaheen, a popular moderate, creates an opening that Republicans are eager to exploit, while Democrats hope Pappas’s incumbency and local appeal can hold the seat. This classic New Hampshire battle promises to be intimate, intense, and unpredictable.