New Hampshire Votes Tuesday to Pick Senate Nominees for Shaheen's Open Seat
Democrats Chris Pappas and Karishma Manzur, and a four-candidate Republican field led by John E. Sununu and Scott Brown, are on the September 8 primary ballot for the seat Sen. Jeanne Shaheen is leaving.
Trump's Endorsement Didn't End the Republican Fight, and Neither Did Polling End the Democratic One
New Hampshire voters go to the polls Tuesday, September 8, to pick nominees for the U.S. Senate seat Democratic Sen. Jeanne Shaheen is leaving when her term ends[1][5]. Shaheen isn't running again, and that single fact is why this race has drawn national money and attention. Open seats are much easier for the other party to flip than ones held by an incumbent, and Senate Republicans have made no secret that they see this as one of their better pickup chances this cycle[5].
Two Democrats are on the ballot: U.S. Rep. Chris Pappas and first-time candidate Karishma Manzur[1][2]. Four Republicans are running: former U.S. Sen. John E. Sununu, former Massachusetts Sen. Scott Brown, Tejasinha Sivalingam and Charlie Hough[1]. The winners of each primary meet in the November 3 general election[1].
What makes Tuesday interesting isn't really the two parties squaring off against each other. It's the fight happening inside each one, over two different questions: whether loyalty to Donald Trump or lobbying experience makes a stronger Republican candidate, and whether Democrats' closeness to pro-Israel donors is a strength or a liability heading into November.
The Endorsement That Didn't Settle Anything
In February, Trump posted his "Complete and Total Endorsement" of Sununu, calling him an "America First Patriot"[5][6]. For a Senate GOP leadership eager to consolidate the field early, that should have been the end of the story. It wasn't.
Sununu spent 2024 as a Trump critic. He endorsed Nikki Haley in that year's presidential primary and wrote an op-ed with the headline "Donald Trump is a loser"[5]. Brown is using exactly that history against him, calling Sununu a "Never Trump" corporate lobbyist who hasn't won an election in 25 years[14]. Brown's own case rests on timing: he backed Trump in 2016, when Sununu was still supporting John Kasich, then served as U.S. ambassador to New Zealand and Samoa during Trump's first term[14][15].
Sununu's answer is that he already held this Senate seat once, lost it in the 2008 Democratic wave, and is the candidate national Republicans believe can win it back[5]. He's not shying away from the Trump endorsement, and it appears to be working: an August poll from the University of New Hampshire Survey Center put him ahead of Brown roughly 60% to 20%[1][4]. That endorsement carries a cost too. Some MAGA-aligned activists called Trump's backing of a former critic a "slap in the face," and the "loser" op-ed remains a live line of attack even with Trump's blessing in hand[5].
A Word That Means Different Things to Different Democrats
On the Democratic side, Manzur has built her campaign around a single argument: Pappas is too close to pro-Israel donors, including AIPAC-aligned money, and Israel's conduct in Gaza amounts to what she calls "genocide"[8]. Pappas rejects that specific framing. He says U.S.-Israel relations are at a turning point and that he can push for policy changes without adopting his opponent's language[8].
This dispute isn't really about New Hampshire. It's a version of a fight happening across Democratic primaries this cycle, over whether officeholders' ties to pro-Israel donors are still acceptable to the party's younger and more left-leaning voters[8]. Manzur, a biomedical scientist who studied Alzheimer's disease and epilepsy, is a member of the Democratic Socialists of America and launched her bid criticizing what she called "dynastic" New Hampshire politics[2][8][16].
She's had real success translating that argument into votes, at least in polling. UNH's survey work shows her rising from 18% to 34% between an April 23 poll and one released in late August, while Pappas fell from 61% to 47% over the same stretch[4][9]. That's a 13-point gap where there was once a 43-point one. Pappas is still the clear favorite. But the shrinking margin is the biggest measured shift in the entire race[4][9].
The Voters Neither Primary Fully Controls
Both fights run into the same structural fact: New Hampshire lets voters register as "undeclared" and then walk into either party's primary on Election Day and pick which ballot to take[13]. As of the state's most recent published registration snapshot, from May 2026, undeclared voters numbered about 377,000 — more than the roughly 314,000 registered Republicans or 265,000 registered Democrats[13][17]. Whichever party's primary looks more consequential that day can pull some of those voters toward its own ballot, which changes who each nominee ends up being chosen by.
That's a big part of why both leading Republicans and Pappas describe themselves as independent voices for New Hampshire rather than national partisans[15]. It's also why Secretary of State David Scanlan's turnout forecast matters beyond bookkeeping. His office projected about 28% turnout, split into an estimated 145,751 Republican and 103,024 Democratic ballots, out of roughly 888,500 registered voters[12]. New Hampshire has backed the Democrat in every presidential race since 2004, but it elected a Republican governor in 2024 and has a Republican legislature — which is why "swing state" is a defensible label here, not a settled one.
How Newsrooms Chose Their Openings
The two Republicans' fight and the two Democrats' fight got very different amounts of coverage depending on which outlet you read. Fox News and the Washington Examiner built their stories almost entirely around Trump's endorsement of Sununu, quoting his "Complete and Total Endorsement" post and the "America First Patriot" label at length[5][6]. Fox's version did note the "loser" op-ed and reported the MAGA-activist backlash to the endorsement — it wasn't pure soft-pedaling. But neither right-leaning outlet mentioned the Democratic primary at all[5][6].
MS NOW and NBC News took the opposite tack, framing the day as a stress test — for Trump's hold on the GOP and for Democratic leadership against its left flank[3][11]. MS NOW's headline described a race "Democrats no longer feel is safe," which treats Manzur's challenge as a threat to be managed rather than a contest with its own merits[3]. NH Journal, a conservative-leaning New Hampshire outlet, read a single UNH poll as evidence Pappas was "losing" on two fronts at once, presenting a within-margin general-election number as settled fact[9]. New Hampshire Public Radio came closest to covering both primaries at comparable length, quoting each candidate's own words rather than leaning on secondhand framing[2][8][14].
What Tuesday Actually Decides
Polls are estimates built from samples, with real margins of error — not results[10]. The only count that matters is the one the Secretary of State reports after the polls close[10]. Three of the four leading candidates are known quantities to New Hampshire voters: Pappas has served in Congress since 2018, Sununu held this Senate seat until 2009, and Brown was a Massachusetts senator before his ambassadorship[2][15]. Manzur is the only newcomer, and she's also the one who moved the most in the polls[4][9].
Whichever Republican and Democrat win Tuesday still have to build a coalition big enough to win an electorate where undeclared voters outnumber either party's registered base[13][17]. What Tuesday settles is only who gets to make that case in November — not whether the case works.
Summary
New Hampshire votes Tuesday, September 8, 2026, in a state primary that picks each party's nominee for an open U.S. Senate seat[1][10]. Democratic Sen. Jeanne Shaheen is retiring at the end of her term, which is why the seat is open[5]. The general election is November 3, 2026[1].
On the Democratic ballot, U.S. Rep. Chris Pappas faces Karishma Manzur, an Exeter biomedical scientist and Democratic Socialists of America member running her first campaign[2][8]. On the Republican ballot there are four names: former U.S. Sen. John E. Sununu, former Massachusetts Sen. and Trump ambassador Scott Brown, Tejasinha Sivalingam and Charlie Hough[1]. President Trump endorsed Sununu in February, calling him an 'America First Patriot'[5][6].
The most-watched dispute is not between the parties — it is inside each one. Manzur says Pappas is too close to pro-Israel donors and calls Israel's conduct in Gaza a 'genocide'; Pappas rejects that framing while saying U.S.-Israel relations are at a turning point[8]. Brown says Sununu is a 'Never Trump' corporate lobbyist who has not won an election in 25 years; Sununu points to his own Senate record and Trump's endorsement[14]. Both Republicans call themselves independent voices for New Hampshire[15].
Polls before the vote showed both leaders ahead but by less than they once were. The University of New Hampshire Survey Center had Pappas over Manzur 47% to 34% in late August — a 13-point gap, down from 43 points in April[4][9]. UNH also showed Sununu leading Brown roughly 60% to 20%[1][4]. Polls are estimates, not results; the actual count is reported by the Secretary of State[10].
The Event
New Hampshire's state primary is being held on Tuesday, September 8, 2026, under the state law setting it for the second Tuesday in September[1][10]. Voters are choosing party nominees for the U.S. Senate seat being vacated by Democratic Sen. Jeanne Shaheen, who is not seeking re-election[5]. Two Democrats — Chris Pappas and Karishma Manzur — and four Republicans — John E. Sununu, Scott Brown, Tejasinha Sivalingam and Charlie Hough — appear on the Senate ballots[1]. Secretary of State David Scanlan forecast turnout of about 28% of roughly 888,500 voters, split into an estimated 145,751 Republican and 103,024 Democratic ballots[12]. The winners advance to the November 3, 2026 general election[1].
Undisputed Facts
- New Hampshire's state primary is Tuesday, September 8, 2026; the general election is November 3, 2026[1].
- Democratic Sen. Jeanne Shaheen is retiring at the end of her term, leaving the seat open[5].
- Four Republicans are on the Senate primary ballot: John E. Sununu, Scott Brown, Tejasinha Sivalingam and Charlie Hough[1].
- Two Democrats are on the Senate primary ballot: U.S. Rep. Chris Pappas and Karishma Manzur[1][2].
- President Trump endorsed John E. Sununu in February 2026, posting that Sununu has his 'Complete and Total Endorsement'[5][15].
- Sununu endorsed Nikki Haley in the 2024 New Hampshire presidential primary and published an op-ed titled 'Donald Trump is a loser'[5].
- Scott Brown served as U.S. ambassador to New Zealand and Samoa during Trump's first term[15].
- A University of New Hampshire Survey Center poll released in late August 2026 put Pappas at 47% and Manzur at 34%; UNH's April 23, 2026 poll had the same matchup at 61%-18%[4][9].
- New Hampshire's registered undeclared voters outnumber either party's registration and may choose either party's ballot at the polls; the most recent published Secretary of State registration snapshot (May 2026) counted about 377,000 undeclared voters against roughly 314,000 Republicans and 265,000 Democrats[13][17].
The Pressure
Strip away the moralizing and blame. What structural realities persist regardless of which narrative wins?
- Senate math
- An open seat is far easier to flip than one with an incumbent. Shaheen's retirement is why national money and attention arrived here at all, and it is why Senate Republican leaders wanted a single strong nominee early[5].
- The undeclared plurality
- The most recent published state registration snapshot (May 2026) counted about 377,000 undeclared voters — more than the roughly 314,000 Republicans or 265,000 Democrats[13][17]. Any candidate who wins a primary by mobilizing the base still has to face an electorate where unaffiliated voters decide. That constraint pushes both eventual nominees toward the same 'independent voice for New Hampshire' language[15].
- Name recognition as an asset that ages
- Three of the four leading candidates are known quantities: Pappas has been in Congress since 2018, Sununu held this seat until 2009, Brown was a Massachusetts senator and later a Trump ambassador[2][15]. Familiarity lowers the cost of a campaign but also means voters already have fixed opinions. Manzur, the only newcomer, had the most room to grow — and grew the most in polling[4][9].
- Gaza as a party-internal fault line
- Manzur's challenge is not really about New Hampshire policy. It is a fight over whether Democratic officeholders' positions on Israel and their pro-Israel donors are acceptable to the party's younger voters[8]. That fault line exists in every Democratic primary this cycle; New Hampshire is where it is being measured on September 8.
Material realityOne U.S. Senate seat is open because Jeanne Shaheen chose not to run again[5]. On September 8, New Hampshire voters pick two nominees, and on November 3 they pick one senator[1]. New Hampshire has voted Democratic in every presidential race since 2004 but elected a Republican governor in 2024 and has a Republican-controlled legislature — so 'swing state' is a defensible label, not a settled fact. Polling before the vote showed both front-runners ahead: Pappas over Manzur 47%-34%, Sununu over Brown roughly 60%-20%[4][9][1]. Polls are samples with error margins; the counted ballots reported by the Secretary of State are the only result[10]. Note also that different registration and turnout figures circulate for different dates: the Secretary of State's own turnout forecast used a base of about 888,500 registered voters for the September 8 primary[12], while the most recent published party-registration breakdown (about 956,000 total, including roughly 377,000 undeclared) dates to May 2026[13][17] — the two are not directly comparable snapshots.
How Each Side Sees It
Each major actor’s view — how it frames things, its underlying incentive, and how it’s materially affected. Tap a side to read it.
Frames it asPappas argues the seat is winnable in November only with a nominee who has already won statewide-scale races. He has represented New Hampshire's 1st District since 2018 — a swingy seat — and says that record is the proof[2]. On Israel, he says U.S.-Israel relations are at a turning point and that he can push for changes in policy without adopting the language his opponent uses[8]. The underlying principle he appeals to is coalition math: a Senate majority is built by holding seats in states that are not safe for either party.
WhyWin the nomination without moving so far left that it costs him undeclared voters in November — the largest single bloc in the state[13][17].
Impact on themA narrow primary win would still show real erosion; UNH measured his lead shrinking from 43 points in an April 23 poll to 13 points in late August[4][9]. In general-election polling he has ranged from a small lead to a small deficit against Sununu[7][9].
Frames it asManzur's case is that the party's problem is not that it is too far left but that it is too close to its donors. She has made Pappas's support from pro-Israel groups, including AIPAC-aligned money, the center of the campaign, and says Israel committed 'genocide' in Gaza[8]. She launched the bid against what she called 'dynastic' New Hampshire politics — the argument that the same family and party names recur for decades while ordinary voters get no real choice[16]. She is a biomedical scientist who studied Alzheimer's disease and epilepsy, and a member of the Democratic Socialists of America[2][8].
WhyConvert issue-based anger — chiefly over Gaza — into a demonstration that a first-time candidate with no establishment backing can move a statewide race[2].
Impact on themHer rise from 18% to 34% in UNH's polling is the single biggest measured shift in the race, driven by younger and self-identified socialist voters[4][9]. Even a loss establishes a benchmark other left challengers will cite.
Frames it asSununu's pitch is electability plus experience: he already held this seat, he lost it in the 2008 Democratic wave, and he is the candidate Senate GOP leaders believe can flip it[5]. He now has Trump's endorsement, which neutralizes the main charge against him[5][6]. He presents himself as an independent voice for New Hampshire rather than a national partisan[15]. The Sununu name is among the best known in state politics — his father was governor and White House chief of staff, his brother Chris was governor.
WhyConsolidate the Republican field early and cheaply so resources go to November, in a seat Republicans see as one of their better flip chances[5].
Impact on themUNH polling put him around 60% to Brown's 20% in the primary and roughly tied with Pappas in a general-election matchup[1][4][9]. He carries the cost of the Trump endorsement too: his 2024 'loser' op-ed remains a live line of attack, including backlash from some MAGA activists who called Trump's endorsement of him a 'slap in the face'[5].
Frames it asBrown's argument is about loyalty and timing. He says he campaigned with Trump in 2016 while Sununu backed John Kasich, served in the first Trump administration as ambassador, and worked with grassroots activists while Sununu 'wooed the D.C. establishment'[14]. He calls Sununu a 'Never Trump' corporate lobbyist who has not won an election in a quarter century[14]. On policy he runs on the One Big Beautiful Bill Act, especially the provisions cutting taxes on tips and overtime — a concrete pocketbook pitch to service and hourly workers[15].
WhyWin the nomination by turning the primary into a referendum on who was with Trump first, rather than on who polls better in November[14].
Impact on themTrailing badly in primary polling and trailing Pappas by more than Sununu does in general-election polls, which is the exact argument Sununu's side uses against him[1][4][7].
Frames it asThe state's rule is that a voter registered as undeclared may walk in on primary day and take either party's ballot[13]. Defenders of the system say it keeps primaries open to people who refuse a party label, and that in a state where undeclared voters outnumber both parties, closing it would disenfranchise the plurality[13][17]. Critics of open primaries argue it lets non-members pick a party's nominee. Here the mechanism matters: whichever party's contest looks more consequential can pull undeclared voters toward its ballot, which changes the electorate each nominee is chosen by.
WhySecretary of State David Scanlan's office is forecasting and staffing for turnout, not advocating an outcome[12].
Impact on themScanlan forecast about 28% of roughly 888,500 voters casting ballots — an estimated 145,751 Republican and 103,024 Democratic[12]. If undeclared voters break toward one ballot, both projections and both primaries shift.
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The Bias Ledger average rating 3.6
The same story, as framed by outlets across the spectrum, ordered least to most biased. The bias score (1 = straight, 10 = heavily spun) is an AI assessment of that framing — click an outlet to see its track record. The tell is the word choice or omission that reveals the angle.
| Outlet | Vantage | Bias | How they frame it | The tell |
|---|---|---|---|---|
| Associated Press | U.S. center; wire service | 1 | 'AP Decision Notes: What to expect in New Hampshire's state primary' — a procedural explainer of ballots, counting and call criteria[10]. | Deliberately verdict-free; the tell is what it leaves out, offering little on why the Gaza dispute or the Trump endorsement is moving voters. |
| New Hampshire Public Radio | U.S. center; public radio, listener- and grant-funded | 2 | Issue-by-issue coverage: 'From Iran war to the economy, differences emerge in NH's Republican Senate primary' and a separate piece on Pappas, AIPAC donations and Manzur[8][14]. | Closest to straight reporting of the set — it reports both primaries at comparable length and quotes each candidate's own words. The 'buzzy primary getting national attention' framing does mildly inflate stakes[2]. |
| Fox News | U.S. right | 3 | 'Trump endorses John E. Sununu over Scott Brown in New Hampshire Senate race' — the story is the endorsement, framed as Trump backing a former critic in a high-stakes swing-state race[5]. | The article does note Sununu's 'Donald Trump is a loser' op-ed and reports MAGA-activist backlash calling the endorsement a 'slap in the face' — it does not fully soft-pedal the tension. The remaining tell is structural: the story is built entirely around Trump's endorsement decision, and the Democratic primary gets no mention at all. |
| NBC News | U.S. left of center | 3 | 'New Hampshire primaries test Trump and the left' — symmetric framing of both intraparty fights as tests[11]. | The 'test' frame is the least loaded available, but it still treats a primary mainly as a forecast of national trends rather than a state choosing nominees. |
| Washington Examiner | U.S. right | 5 | 'Trump endorses "America First Patriot" John Sununu in New Hampshire Senate primary' — quotes the endorsement label directly in the headline[6]. | Putting a campaign phrase in quotation marks in the headline carries it to readers who never open the story. The Democratic primary barely features. |
| MS NOW | U.S. left | 5 | 'New Hampshire votes today in a Senate race Democrats no longer feel is safe'[3]. | Leads with Democratic anxiety rather than the ballot. 'No longer feel is safe' is a mood, and it makes the Republican primary a threat rather than a contest with its own stakes. |
| NH Journal | U.S. right; New Hampshire conservative-leaning outlet | 6 | 'Pappas Losing to Sununu, Losing Ground to Manzur in Latest UNH Survey' — one poll read entirely as Democratic decline[9]. | Two verbs, both 'losing,' from a single survey. A within-margin general-election number is reported as an established fact of the race. |
References
- United States Senate election in New Hampshire, 2026 — Ballotpedia · U.S. nonpartisan election reference; funded by the Lucy Burns Institute
- NH's Senate race: A buzzy primary getting national attention — New Hampshire Public Radio · U.S. center; NPR member station, listener- and grant-funded
- New Hampshire votes today in a Senate race Democrats no longer feel is safe — MS NOW · U.S. left; successor brand to MSNBC
- Support for Pappas dwindles in U.S. Senate race as GOP, progressive challengers climb in the polls — Concord Monitor · U.S. center-left; New Hampshire daily newspaper
- Trump endorses John E. Sununu over Scott Brown in New Hampshire Senate race — Fox News · U.S. right; owned by Fox Corporation
- Trump endorses 'America First Patriot' John Sununu in New Hampshire Senate primary — Washington Examiner · U.S. right; owned by Clarity Media Group (Philip Anschutz)
- 2026 New Hampshire Senate — Sununu vs. Pappas polling average — RealClearPolling · U.S. right-of-center polling aggregator
- Pappas says U.S.-Israel relations at turning point, as primary rival blasts AIPAC ties — New Hampshire Public Radio · U.S. center; NPR member station
- Pappas Losing to Sununu, Losing Ground to Manzur in Latest UNH Survey — NH Journal · U.S. right; New Hampshire conservative-leaning news site
- AP Decision Notes: What to expect in New Hampshire's state primary — Associated Press · U.S. center; nonprofit news cooperative
- New Hampshire primaries test Trump and the left — NBC News · U.S. center-left; owned by NBCUniversal
- NH expected to have strong turnout for Tuesday's primary — New Hampshire Union Leader · U.S. right-of-center; New Hampshire daily with a conservative editorial page
- Voting in Party Primaries — New Hampshire Secretary of State · U.S. state government; official election administrator
- From Iran war to the economy, differences emerge in NH's Republican Senate primary — New Hampshire Public Radio · U.S. center; NPR member station
- U.S. Senate: Here's what separates Manzur and Pappas, Brown and Sununu — New Hampshire Bulletin · U.S. left-of-center; States Newsroom nonprofit network
- Manzur launches Senate primary bid against 'dynastic' NH politics — New Hampshire Union Leader · U.S. right-of-center; New Hampshire daily
- Party Registration History 1970-2026 — New Hampshire Secretary of State · U.S. state government; official election administrator