New Hampshire Senate 2026 Odds: Pappas Vs. Sununu Verdict

New Hampshire votes for a U.S. senator on Tuesday, November 3, 2026, for the first open Senate seat the state has seen in years: three-term Democrat Jeanne Shaheen is retiring, and the presumptive matchup is Democratic U.S. Representative Chris Pappas against former Republican U.S. Senator John Sununu, with the parties' September 8 primaries still to come. Kalshi has turned it into a market, one yes/no contract per party, and we asked our AI model panel to score the race without letting any of them see a single price. They came back agreeing with the market on the favorite and disagreeing sharply on how close it really is.

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The Quick Answer

Kalshi's market prices the Democratic side (Chris Pappas) near 88 cents and the Republican side (John Sununu) near 12 cents, treating this open seat as close to safe for the Democrats. Our price-blind, six-model panel is far less certain: it blends the Democratic side to about 65% and the Republican side to about 35%. Both agree the Democratic side is the favorite; they split on how safe he is. The market is pricing a consistent Democratic polling lead, a huge cash edge, and a state that has not elected a Republican to the Senate since 2010. The panel is pricing the things that lead sits on top of: an open seat with no incumbent, a primary that has not happened yet, and a New Hampshire Senate history that produced a race decided by about 1,000 votes the last time Republicans nominated a strong statewide name.

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• Market Favorite: Democratic side (Chris Pappas), ~88¢
• Model Favorite: Democratic side (Chris Pappas), ~65% blend, agreeing with the market on the winner
• The Gap: the panel prices the Republican about 23 points above his ~12-cent market, fading a near-safe Democratic price toward a competitive open seat
• The Tension In One Line: every public poll has Pappas ahead, but only by single digits with the primary still to come, so the panel read an 88-cent Democrat as overpriced rather than a settled result
• The Panel's Logic: New Hampshire's Democratic lean, Pappas's cash edge, and the midterm wind against the president's party keep him favored, but a strong Republican in an open seat, before either nominee is even set, is not a 12-cent underdog

The case for Pappas, where Sununu's real path runs, the full board, the polling, the open-seat picture, and a plain-English guide to reading these prices are all below.

The Market At A Glance

Venue	Kalshi, a CFTC-regulated event-contract exchange (18+; availability varies by state, as of August 2026)
The Event	"New Hampshire Senate winner?" (Kalshi event SENATENH-26), one yes/no contract per party
The Contract	The Democratic market resolves YES if a Democrat is sworn in as New Hampshire's Class 2 senator for the term beginning in 2027; the Republican market resolves YES if a Republican is. It pays on the winner's party, not the named candidate
Liquidity (As Of August 8, 2026)	An actively followed board, per Kalshi's live market data: the Democratic and Republican contracts carry roughly 43,000 and 65,000 contracts (each $1 notional) in open interest. Live two-sided quotes were unquoted at this snapshot, so the prices below come from recent daily-candle closes rather than a continuous tight bid/ask; treat the exact cents as indicative, not depth-tested
Snapshot	Prices as of August 8, 2026 (latest snapshot; prices on this page refresh during the news wave into November). Verdicts generated August 8, 2026

These are model estimates, not predictions of fact and not financial or voting advice. Kalshi event contracts trade on a CFTC-regulated exchange; you must be 18 or older and in an eligible state to participate, and this article does not advocate for or against any candidate or party. Every number in this piece gets graded in public once the market settles, in the full graded Model Verdict scoreboard.

What Actually Decides This Race

Before either name, five fetched facts define the board, and they pull in opposite directions:

• This Is An Open Seat, And The Nominees Are Not Final. Jeanne Shaheen is not seeking a fourth term, so neither side carries an incumbency advantage. The state primaries are September 8, 2026, which means the matchup below is presumptive: Democratic U.S. Representative Chris Pappas, a four-term member from the 1st District, leads his primary field with the party establishment behind him, and former Republican U.S. Senator John Sununu leads the GOP field, with a Trump endorsement, over former Massachusetts Senator Scott Brown. Until September 8 the Republican nominee's identity is a live sub-question, because a Sununu general election and a Brown general election are not equally competitive.
• New Hampshire Leans Democratic At The Top Of The Ticket, But Only Barely. Kamala Harris carried the state 50.65% to 47.87% in 2024 (about D+2.8), the closest presidential margin by raw votes of any state that year. It stayed blue, but it is not a safe-blue state at the presidential level, and that thin lean is the backdrop the whole board sits on.
• The Recent Senate History Swings From A Blowout To A Coin Flip. Shaheen won re-election 56.63% to 40.99% in 2020 (about D+15.6), sweeping every county against a weak opponent. But in 2016 Maggie Hassan unseated Republican Kelly Ayotte 48.0% to 47.9%, a margin of roughly 1,000 votes, the closest Senate race in the country that cycle. New Hampshire Senate races can compress to the razor's edge when Republicans field a strong statewide brand, as they did in 2016.
• The Money Strongly Favors The Democrat. Chris Pappas's federal filing through June 30 showed roughly $13.37 million raised for the cycle and about $5.18 million cash on hand, including about $3.5 million in the second quarter. On the Republican side, per their second-quarter FEC filings, John Sununu reported about $1.5 million raised in the second quarter with roughly $2.7 to $3.0 million cash on hand, and Scott Brown about $279,000 in the quarter. Pappas enters the general having raised more for the cycle than any Republican in the field by a wide margin. Nationally, the president's party has lost House seats in 18 of the last 20 midterms, a structural wind at the Democrats' back this cycle.
• The Raters Cluster On Lean Democratic, And The Polls Back It By Single Digits. Cook Political Report rates the race Lean Democrat as of its June 30 rating, Sabato's Crystal Ball has it Leans Democratic, and Inside Elections lists it Tilt Democratic. The public head-to-heads all have Pappas ahead of Sununu but never comfortably: a late-June UNH Survey Center poll had it 47-44, an April UNH poll 49-42, and an Emerson College poll in late March 45-44. Every lead points one direction; none of them is large.

That framework is the whole story of this board. The market weights the consistent Democratic lead, the cash gap, and the state's blue tint into a near-safe Democratic seat. The models, working from the same fetched facts, weighted the open seat, the not-yet-settled primary, and New Hampshire's history of tight Republican-fielded races more heavily, and priced the Republican side far above its market.

Here is the short version first, then every model's raw number.

The Board

Outcome	Nominee & status	Market	Model blend
Democratic	Chris Pappas (four-term U.S. Rep, NH-01; presumptive nominee)	~88¢	65.2%
Republican	John Sununu (former U.S. Senator; presumptive, primary Sept 8)	~12¢	34.8%

More live boards from the same panel: Georgia Senate model verdict (Democratic ~92¢ / Republican ~9¢), Maine Senate model verdict (Democratic ~64¢ / Republican ~37¢), and Iowa Senate model verdict (Republican ~60¢ / Democratic ~41¢). Prices fetched August 8, 2026.

Every Seat's Number

Numbers below are each seat's probability that the named party wins the seat, after the revision round. The two rows are complements, because this is a closed two-way race.

Outcome	Market	Fable	Opus	Sonnet	GLM	Kimi	DeepSeek	Blend	Gap (blend% − mkt¢)
Democratic (Chris Pappas)	~88¢	74.0	68.0	68.0	62.0	64.0	55.0	65.2%	-23
Republican (John Sununu)	~12¢	26.0	32.0	32.0	38.0	36.0	45.0	34.8%	+23

These are model estimates, not predictions of fact and not financial or voting advice. The Blend column is the simple mean of the six model numbers shown in its row. The last column is a quick directional gap, the blend percentage minus the raw market price in cents. Because this is a closed two-way race, the two prices sum to about 100 cents, so there is almost no vig to remove, and the panel sits well to the Republican side of the market: agreeing that Pappas is the favorite, but pricing the Republican's 12-cent contract up to about 35%. The models scored the party outcomes, which is exactly how the contract settles.

A note on the panel. Our standard Model Verdict lineup runs eight seats. On this run three were unavailable: the ChatGPT, Gemini, and Grok command-line seats were not installed on the machine that produced these verdicts. This board therefore runs on six models: Claude Fable, Claude Opus, Claude Sonnet, GLM, Kimi, and DeepSeek. All six scored the race on August 8, 2026, without seeing any prices, working from a fetched, dated summary of the candidates, the September primary picture, the race ratings, the structural voting history, fundraising, and the live head-to-head polls. All six then read one another's anonymized reasoning and revised. Every model's number also lands in our back-tested Model Verdict ledger, where past price-blind calls are graded against settled results so the method is measured, not just asserted.

The board comes down to two forces: the near-safe Democratic price the models trust less than the market does, and the competitive open-seat case a single-digit poll lead and an unsettled primary still build.

The one line that explains the whole board: every public poll has Pappas ahead, but the panel priced the Republican far above the market because a single-digit lead in an open seat, before either party has even picked a nominee, reads to the models as a competitive race rather than one with a near-locked 88-cent favorite. — the panel consensus

The Democratic Side: Why Chris Pappas Is Favored

Every seat made Pappas the favorite, and the case is not ideology, it is the weight of consistent signal. Opus, holding at 68%, put the core of it plainly, noting that three independent handicappers all land Democrat-favored-but-not-safe and that every public head-to-head has Pappas ahead, never a single lead for Sununu, with a lopsided cash advantage on top. Sonnet, also at 68%, stacked the same inputs: consistent Lean-D ratings, Pappas's polling edge of one to seven points over Sununu, a roughly two-to-one fundraising lead, and the midterm headwind against the president's party.

The second pillar is money and the national environment. Pappas's fundraising edge is not marginal, he has raised $13.37 million for the cycle, more than any Republican rival by a wide margin, and the president's party has lost House seats in 18 of the last 20 midterms. Kimi, weighing the Democratic case even while landing at the competitive end of the panel, credited that Pappas "leads every head-to-head poll, holds a commanding fundraising edge, and midterms historically punish the president's party."

The favorite's thesis in one line: a consistent, if narrow, polling lead sitting on top of a two-to-one cash advantage, a Lean-Democratic rater consensus, and a midterm wind against the president's party is why six price-blind models all made the Democratic side the favorite. — the panel consensus

Not every seat pushed to the same place, and the disagreement inside the panel is honest. Fable sat highest at 74%, closest to the market, trusting the uniform Democratic signal the most. GLM and DeepSeek sat lowest, at 62% and 55%, closest to a true competitive race. That spread, 55 to 74 on the same fetched facts, is a judgment-call spread, not an information gap, and it is exactly why the blend lands in the mid-60s rather than near the market's 88.

The Republican Side: John Sununu's Path

Sununu is not a longshot on this board, he is a live underdog the panel prices at about 35%, nearly three times his ~12-cent market and far from dismissed. The models are clear about where his path runs and why the market likes it so much less than they do.

The strongest case for the Republican rests on three fetched facts the panel took seriously. First, the open seat itself: with no incumbent to defeat and neither party's nominee even chosen until September 8, the structural advantage an incumbent would carry is simply absent. Second, the specific state history: Kimi flagged that "New Hampshire's 2016 Senate race was decided by ~1,000 votes when Republicans fielded a strong nominee," and Sununu, a former senator with statewide name recognition and a Trump endorsement, is that kind of nominee. Third, the polls themselves: the leads are real but small, averaging roughly three to five points about twelve weeks out with high single-digit undecideds, and one nonpartisan Emerson poll had it inside a point.

Why the models still kept him behind: the panel reads the polls as a Democratic edge, not a Republican one, and it respects the money and rating gap. Fable, even while landing most Democratic, captured the balance in its revision, writing that the polling lead "is consistent but not overwhelming, and the trend within it matters: UNH went from Pappas +7 in April to Pappas +3 in June, with ~9% undecided in an open-seat race where neither candidate carries incumbency." The models price a competitive race, they just price the lean, the cash, and the ratings as forces that keep the Democrat favored rather than forces that make the seat safe.

Where The Panel Changed Its Mind

After round one, every seat read the other five's anonymized reasoning and could revise. The movement was small but pointed, and the arcs are worth reading because they show exactly which argument carried weight.

• GLM Revised Up, 58% To 62% For The Democrat. In its own words: "Peers surfaced the compounding logic I underweighted: that multiple independent structural advantages (midterm base rate, cash edge, rater consensus) stacked on top of a consistent-if-narrow polling lead should produce more than a 58% probability." It still held below the panel's cluster, citing the closeness of the most recent poll (June, +3 with 9% undecided). — GLM
• Fable Revised Down, 77 To 74 For The Democrat. "Peers surfaced two things I had under-weighted rather than not seen: the 2016 razor-edge precedent is mechanism, not trivia, it shows NH Senate races compress specifically when Republicans nominate a strong statewide brand, which describes Sununu exactly; and the within-cycle tightening (UNH +7 April to +3 June) deserved weight I didn't give it." — Fable
• Opus Held At 68%, And Said Why. "No peer surfaced evidence or a mechanism I had not already weighed. The panel spans 58 to 77 on the same facts. The lower seats make the strongest opposing case, Sununu's statewide strength, NH's razor-thin 2016 precedent, early-snapshot polls, but they underweight how uniform the Democratic signal is across polls, ratings, and money." — Opus

The net effect was almost nothing on the headline, the blend moved by a fraction of a point, which is itself the finding: reading each other's reasoning did not collapse the panel toward a number, it left a stable, well-argued spread from the mid-50s to the mid-70s on the Democratic side.

What Would Change The Panel's Mind

This is a board with a calendar in front of it, and several concrete events could move the number in a known direction:

• The September 8 Primary Result. If John Sununu wins the Republican nomination as expected, the panel's competitive read holds. If Scott Brown or a weaker candidate wins instead, the Republican side likely falls toward the market, because the panel's whole case for pricing the Republican near 35% leans on a strong statewide nominee.
• A Fresh Nonpartisan Poll. If UNH or Emerson show Pappas's lead widening back toward the +7 of April or beyond, the panel moves toward the market and the Democratic number rises. If a poll shows the race tied, the panel moves further from the market and the Republican number rises.
• The National Environment. A drop in the president's party's standing, or a clear deepening of the midterm wind, pushes the Democratic side up. A rally-around-the-flag national event, the kind that flipped the 1998 and 2002 midterms, would push the Republican side up.
• The Q3 Fundraising Picture (mid-October Filings). If Sununu closes the cash gap or national Republican money reserves heavily in New Hampshire, the Republican number firms. If Pappas's advantage widens further, the Democratic number does.

Dark Horses The Panel Won't Dismiss

The named board is two-way, but the fetched record and the settlement mechanic leave a few scenarios the panel flagged rather than ignored:

• The Primary Produces A Weaker Republican. The entire competitive case here assumes Sununu, the strong statewide name, is the nominee. If the September 8 GOP primary goes another way, the ~12-cent Republican contract may be closer to fair than the panel's 35%, and the market's near-safe Democratic price becomes the better read. The 23-point gap between the models and the market on the Republican line is the size of that disagreement, and the primary is its first test.
• The Lean Is Finally Hardening. Every Republican-side argument leans on the 2016 near-miss and the open seat. If New Hampshire's Democratic lean is quietly strengthening the way its 2020 Senate blowout and its all-Democratic delegation suggest, then a consistent single-digit lead plus a two-to-one cash edge is a near-lock after all, and the market at 88 is right.
• The Party-Not-Person Settlement Tail. Because these contracts pay on party, a third-party or independent winner, or a party switch before the January 2027 swearing-in, would resolve both the Democratic and Republican markets to No. This is a negligible outcome in a two-major-party New Hampshire race, but it is why neither contract tracks the named candidate directly.

The Traps: Rows That Look Like Signal But Are Not

Transparency matters more than a clean story, so here is where the board could mislead you:

• A Single-Digit Lead Is Not A Settled Result, And It Is Not A Tie Either. Pappas leads every poll, which is easy to read as a lock, and the leads are small, which is easy to read as a coin flip. The panel's thesis is neither: a consistent three-to-five-point lead twelve weeks out in an open seat is a real Democratic edge that is not yet safe. The market and the models weight that same lead differently, and November settles who is right.
• A 23-Point Gap Is A Disagreement, Not A Proven Mispricing. The panel sits about 23 points above the market on the Republican line. That is a real clash of methods, the models trust the open seat and the not-yet-set primary more, the crowd trusts the consistent lead and the cash more, not a declared edge sitting on the table.
• The Unset Primary Cuts Both Ways. The panel's competitive read depends on Sununu being the nominee. That is the most likely outcome, but it is not certain until September 8, and reading the Republican side as a firm 35% before the nominee is chosen is its own small leap.

How To Read This Board

The board sorts into three honest reads, and which one fits depends on how much weight you put on the consistent lead versus the open-seat uncertainty.

• You Trust The Signal: The Democratic Side. A consistent poll lead, a two-to-one cash advantage, a Lean-Democratic rater consensus, a state that has not elected a Republican senator since 2010 (Kelly Ayotte, who then narrowly lost that seat in 2016 to Maggie Hassan), and a midterm wind against the president's party are the case every model made for keeping Pappas the favorite.
• You Trust The Structure: The Republican Case. An open seat with no incumbent, a primary not yet held, a strong statewide Republican in Sununu, and a state that produced a 1,000-vote Senate race in 2016 are why the panel prices the Republican near 35% and reads the 12-cent market as too low.
• You Want The Honest Bottom Line: A Democratic Favorite The Market Prices Far Safer Than The Models Do. The forecasters rate it Lean Democratic, the market treats it as near-safe, and our panel treats it as clearly competitive. The interesting thing is not the favorite, both agree on that, but the size of the edge, and it settles in public in November.

How To Read These Prices

The models can tell you where they part ways with the crowd, but the number in front of you still has to be understood in context. Here is how to read a market like this one, plus the honest friction of an event-driven board.

Work an example. Say the Democratic contract shows an 88-cent YES price. Taken at face value, that implies about an 88% chance a Democrat wins the seat. To get a fair, spread-free read you normalize the whole field so every outcome's price sums to 100. On most prediction-market boards the raw prices sum to more than 100 because each contract carries its own bid/ask spread, and de-vigging pulls the numbers back toward a clean total. This board is a clean two-way that already sums to about 100, so there is almost nothing to remove, and 88 for the Democrat stays near 88%. The lesson holds anyway: always check what a fair version of a price looks like before comparing it to anything, which is the whole idea behind converting Kalshi's cents into real odds before leaning on any number.

That same discipline of comparing a number to its fair value is what line shopping and finding the +EV side is about. OddsShopper's odds screen and free expert picks cover the sports slate rather than election futures, and the New Hampshire race itself lives on Kalshi, but the method is the same one our Maine Senate model verdict, our Georgia Senate model verdict, and our Iowa Senate model verdict use on related fields, and it complements our broader 2026 Senate election odds breakdown of the whole chamber and our balance-of-power model verdict. Every number here also lands in our back-tested Model Verdict ledger.

A few honest points before reading too much into any number in the table above:

• Eligibility. Kalshi is a CFTC-regulated event-contract exchange, not a sportsbook. You must be 18 or older and located in an eligible state, and availability varies by state and can change.
• Liquidity And Spread. This board carries tens of thousands of contracts of open interest, but its live two-sided quote was thin at the snapshot, so the prices here come from recent daily-candle closes rather than a continuous tight bid/ask. Treat the exact cents as indicative, and expect your fill to depend on the spread at the moment you act.
• A Moving Story. This race has an unset primary, a competitive challenger, and an election three months out; new events before November 3 can move it, and these estimates reflect only what was known on August 8. Prices shown on this page refresh during the news wave into November.
• Not Advice. Everything here is analysis for information, not a recommendation to trade or to vote. These are model estimates, not predictions of fact and not financial or voting advice.

Settlement Timeline

Settlement	Resolves when the winner is sworn in as New Hampshire's Class 2 senator for the term beginning in 2027 (early close on swearing-in, around January 2027); effectively decided by the November 3, 2026 general election
Next Catalysts	September 8, 2026 state primaries (sets both nominees); fall 2026 debates; mid-October Q3 FEC filings; November 3, 2026 general election
Re-Score Policy	We re-score this board when the story moves: a primary result, a new poll, a debate, or a rating change. As of August 8, 2026, the panel sits at Democratic 65% / Republican 35%, against a market of Democratic 88¢ / Republican 12¢

FAQ

Who is favored to win the 2026 New Hampshire Senate race? Both the market and our AI panel favor the Democratic side, presumptive nominee Chris Pappas, but by very different amounts. Kalshi's market prices the Democratic contract near 88 cents and the Republican side near 12, treating the seat as close to safe for the Democrats. Our price-blind, six-model panel is far less certain, blending the Democratic side to about 65 percent and the Republican side to about 35. Both agree on the favorite and split hard on how safe he is.

What do the New Hampshire Senate polls say about Pappas vs Sununu? Every public head-to-head has Chris Pappas ahead of former Senator John Sununu, but by single digits. A UNH Survey Center poll fielded June 18 to 23 had Pappas up 47-44, an April UNH poll had it 49-42, and an Emerson College poll in late March had it 45-44, with the same survey showing Pappas 48-39 over Scott Brown. The average lead is roughly three to five points about twelve weeks out, with high single-digit undecideds, which the panel reads as a competitive open seat rather than a lock.

Why does the AI panel disagree with the market on this race? The market prices New Hampshire's Democratic lean, Pappas's consistent polling lead, and his large cash advantage as close to decisive, pushing the Democratic side up near 88 cents. The panel weights all of that too, but leans harder on the open seat with no incumbent, the fact that the September 8 primaries have not been held so the Republican nominee is unsettled, and New Hampshire's own history of razor-thin Senate races when Republicans field a strong statewide name, as in 2016. On that weight the panel keeps the Democratic side near 65 percent rather than a near-lock.

Is the 2026 New Hampshire Senate seat an open seat? Yes. Three-term Democratic incumbent Jeanne Shaheen announced she would not seek re-election, so no incumbent is on the 2026 ballot. The state primaries are September 8, 2026, so the nominees are not final. Democratic U.S. Representative Chris Pappas and former Republican U.S. Senator John Sununu lead their respective primary fields in public polling, with the general election set for November 3, 2026.

How does the Kalshi New Hampshire Senate market settle? Kalshi lists one yes/no contract per party. The Democratic contract resolves YES if a Democrat is sworn in as New Hampshire's Class 2 senator for the term beginning in 2027, and the Republican contract resolves YES if a Republican is. It pays on the winner's party, not the named candidate, so a third-party or independent winner, or a party switch before swearing-in, would resolve both markets to No.

How were these model estimates produced? Six AI models scored the race without seeing any market prices, working from a fetched, dated summary of the candidates, the September primary picture, race ratings, structural voting history, fundraising, and the live head-to-head polls, then read one another's anonymized reasoning and revised. Their numbers were blended into one estimate per party. These are model estimates, not predictions of fact and not financial or voting advice.

The Bottom Line

The market and the models are looking at the same race and agreeing on the favorite while splitting hard on the margin, which is what makes this board worth reading. Kalshi prices the Democratic side near 88 cents and the Republican near 12, treating the seat as close to safe, on Pappas's consistent lead, his cash edge, and the state's blue tint. Our panel keeps Pappas at about 65 percent and the Republican at about 35 on the weight of an open seat, a primary that has not happened, and a New Hampshire that produced a 1,000-vote Senate race the last time Republicans nominated a strong statewide name. The read to take is not that Pappas is safe, and not that the race is a toss-up, but that a single-digit lead in an unsettled open seat is not the same as an 88-cent lock, which is why six price-blind models priced the Republican far above his market. If this method is your thing, our Maine Senate model verdict and our guide to Kalshi versus Polymarket are the natural next reads.

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