Tools chosen: polymarket_direct kalshi_related polymarket_related claude_news claude_news gdelt_news wikipedia code_execution

Sub-questions (Fermi decomposition)

Planner reasoning

This is a Polymarket election market on the open NH Senate seat (Shaheen retiring), so the primary anchor is the Polymarket price plus any Kalshi equivalent. Key drivers are candidate fields (Chris Pappas vs. Scott Brown/John E. Sununu), NH partisan lean and 2026 national environment, and polling. I'll pull direct prices, cross-venue comparison, news/polling searches, and background.

# Current state Kalshi's own market ("New Hampshire Senate winner? — Democratic party" equivalent, ticker 0xfc5c...) has no directly reported YES price in this research pull; the closest primary anchor is Polymarket's near-identical contract at 85.5%. The seat is open (Shaheen retiring), Democrat Chris Pappas is the clear primary frontrunner, and the GOP primary (Sept 8, 2026) between John E. Sununu and Scott Brown remains unresolved, with Sununu heavily favored. General-election polling has tightened from a Pappas +7 lead (April) to a near-tie (Aug 2026), even as nonpartisan raters (Cook, Sabato, Inside Elections) still call the race "Lean/Tilt Democratic." # Timeline of key events - 2014-11: Scott Brown loses NH Senate race to Jeanne Shaheen (confirmed, Wikipedia). - ~2025 (undated): Jeanne Shaheen announces retirement, opening the seat for the first time since 1990 (confirmed, Wikipedia/Ballotpedia). - Early 2026: Chris Pappas (D) and Scott Brown (R) launch campaigns; John E. Sununu later enters GOP primary via campaign video (confirmed, CBS/NBC/Yahoo). - 2026-03: Cook Political Report and Sabato's Crystal Ball rate the general election "Lean Democratic"; Inside Elections rates "Tilt Democratic" (confirmed, Cook Political Report). - 2026-03: Emerson poll shows Pappas 45%–Sununu 44%, within margin of error (reported, The Hill). - 2026-04 (late): UNH Survey Center poll: Pappas leads Dem primary 61%; Sununu leads GOP primary 56–19 over Brown; Pappas leads Sununu 49–42 general (reported, UNH/NH Review). - 2026-06/07: UNH poll: Pappas 47%–Sununu 44% (reported, NHPR); Q2 fundraising reports show Pappas ~$3.5M raised since April ($5.1M COH) vs Sununu ~$1.5M ($3M COH) vs Brown ~$279K ($736K COH) (confirmed, NHPR/Valley News). - 2026-08 (late): UNH/7NEWS poll shows race "statistically tied," Sununu 45%–Pappas 43%; Sununu leads Brown primary by 33 pts in RCP average (reported, Newsweek/WHDH). - Ongoing: Primary scheduled 2026-09-08; general election 2026-11-03 (confirmed, Ballotpedia/Wikipedia). # Event Will the Democratic nominee win the 2026 New Hampshire U.S. Senate general election? # Outcomes to forecast - Yes (Democrat wins) - No (Republican or other wins) # Kalshi market anchor No direct Kalshi YES price was returned in this research pull for the target ticker itself; related Kalshi markets (NH Governor-R at 88%, NY Senate-D 2028 at 88%, national Senate control markets ~55-56% D) provide context but not a direct anchor. **Use Polymarket's near-identical contract (85.5% YES, -4% 7d, +2% 30d, $57.5K volume, range 75.5–89.5% over 119 days) as the best available cross-venue proxy anchor**, since no Kalshi-specific price for this exact ticker was retrieved. # Sub-question answers 1. **Polymarket price/trend** — 85.5% currently; down 4pts over 7 days (likely reflecting tightening Aug polls) but up 2pts over 30 days; range 75.5–89.5% over past 119 days. [polymarket_direct] 2. **Kalshi/other venues** — No direct Kalshi price for this ticker found; related Kalshi markets (NH Governor-R 88%, national Senate control ~55-56% D) don't directly cross-reference this race. Cross-venue disagreement can't be confirmed. [kalshi_related] 3. **Candidates** — Democrat: Chris Pappas (frontrunner, also Karishma Manzur running). Republicans: John E. Sununu and Scott Brown (primary Sept 8, 2026), Sununu strongly favored (59% vs Brown's 20% in one poll; leads by 33 pts in RCP primary average). No credible independent spoiler identified. [claude_news, Wikipedia, Ballotpedia] 4. **Polls/fundraising** — General-election polls moved from Pappas +7 (April UNH) to a statistical tie (Aug UNH/7NEWS: Sununu 45–Pappas 43; Emerson March: Pappas 45–Sununu 44). Pappas has a dominant financial edge: ~$13.4M raised cycle-to-date vs Sununu ~$3.7M and Brown ~$1.9M. [NHPR, claude_news, integrityindex.us] 5. **Historical base rate/lean** — NH Dem margins 2014-2024 average +5.5pts (median +3.2); recent cycles (2020/22/24) average +9.2pts. Harris won NH by 2.8pts in 2024 (down from Biden's 7.3pt win in 2020). Ayotte (R, 2016) is the last NH Republican Senate winner. [code_execution, quantus.substack] 6. **National midterm environment** — Generic ballot averages D+6.4 to +6.7 (Silver Bulletin, RealClearPolling, mid-Aug 2026); Trump approval underwater (~38% approve/58% disapprove). Historically favors the out-party (Democrats) in 2026 midterms. [claude_news] 7. **Race ratings** — Cook Political Report, Sabato's Crystal Ball: "Lean Democratic" (as of March 2026, seemingly unchanged despite Aug tightening); Inside Elections: "Tilt Democratic." Cook explicitly says despite GOP bullishness on a tied Emerson poll, "we have a hard time seeing Republicans pulling off the upset" given the midterm environment. [Cook Political Report] # Key facts (high-confidence, factual) 1. [Wikipedia] Open seat; Shaheen retiring; first open NH Senate race since 2010. 2. [Ballotpedia] GOP primary (Sununu vs. Brown) and Dem primary (Pappas vs. Manzur) held Sept 8, 2026; general Nov 3, 2026. 3. [NHPR/integrityindex.us] Pappas has overwhelming fundraising lead (~$13.4M vs. Sununu $3.7M, Brown $1.9M cycle-to-date). 4. [Cook Political Report] Cook/Sabato rate "Lean D," Inside Elections "Tilt D" as of latest available rating (March 2026). 5. [UNH/7NEWS, Aug 2026] Most recent general-election poll shows a statistical tie (Sununu 45–Pappas 43). # Cross-market signals - Kalshi related: No direct price for this ticker; adjacent Kalshi markets (NH Gov-R 88%, national D Senate control ~55-56%) don't pin this race directly. - Polymarket: 85.5% YES (Dem), softening slightly (-4% in 7 days) alongside tightening polls, but still well above 50/50 and up net 2pts over 30 days. - Sportsbook implied: None found. # Analyst opinions and speculation - RedState (Aug 2026): frames NH as an underrated GOP flip opportunity given Emerson/UNH tightening — a minority/contrarian view relative to Cook/Sabato consensus. - Cook Political Report explicitly rebuts GOP optimism, citing unfavorable midterm environment for the incumbent party (Republicans) as reason Dems likely hold. - Code-execution base-rate model (fundamentals + midterm swing) estimates 87–98% Dem win probability, centering ~90-95%, broadly consistent with Polymarket's 85.5% but somewhat more bullish for Democrats. # Directional lean per outcome - **Yes (Dem win)**: Supported by Pappas's fundraising dominance, favorable generic ballot (D+6-7), historically blue-trending NH federal results, Cook/Sabato/Inside Elections "Lean/Tilt D" ratings, Polymarket at 85.5%. - **No (GOP win)**: Supported by recent poll tightening (Pappas +7 in April → statistical tie in Aug), Sununu's strong name recognition/political lineage, open-seat volatility (no incumbent), Polymarket's -4% 7-day trend suggesting some market softening on Dem chances. # Gaps / unknowns - No confirmed Kalshi YES price for this exact ticker retrieved — anchor is inferred from Polymarket only. - GOP nominee not yet determined (primary Sept 8, 2026); Brown could theoretically win, altering matchup dynamics though seen as less likely. - No post-August polling captured; race could continue trending tighter or reverse. - Independent/third-party filing status not detailed. # Calibration anchors - Polymarket (proxy) YES price: 85.5% (7d: -4%, 30d: +2%). - Base-rate/fundamentals model: ~87-98% (central ~90-95%) Dem win probability. - Nonpartisan rating consensus ("Lean/Tilt Democratic") historically corresponds to ~75-90% win probability for the favored party in Senate races.

1. Both forecasters anchor almost mechanically on the Polymarket 85.5% figure without grappling with the fact that this is a *thin, low-volume* market ($57.5K volume) that already shows a -4pt 7-day drift toward the GOP—neither seriously discusses whether the market itself might be lagging the August tie poll, which could argue for further downward adjustment rather than settling right at the stale anchor. 2. Neither forecast addresses the divergence between the polling trend (Pappas +7 → tied) and the "Lean/Tilt Democratic" ratings explicitly noted as unchanged "despite Aug tightening" — this is a real inconsistency in the evidence (ratings may be stale) that deserves more scrutiny rather than being cited as simple confirmation of the Dem edge. 3. Both forecasts ignore the "code-execution base-rate model" estimate of 87-98% (~90-95% central) — they mention it but don't explain why they land 5-10pts below it purely by defaulting to the market price, which is somewhat circular reasoning (using the model as a sanity check but then overriding it without much justification). 4. Neither forecast meaningfully engages with the unresolved GOP primary risk: if Brown (not Sununu) wins, the brief flags this "could alter matchup dynamics" — a scenario that could either help or hurt Democrats but is treated as a non-factor in both rationales. 5. Both forecasts converge to identical 85/15 outputs despite differing confidence levels (0.62 vs 0.72) and different rationales emphasizing different evidence — this convergence itself is suspicious and neither independently stress-tests whether the true uncertainty band should be wider given the "no post-August polling" gap and three months remaining until the election. 6. Neither forecaster discusses historical Senate polling error/tightening patterns in open-seat midterm races (e.g., how often a April +7 lead becomes a final loss) to calibrate how much weight the August tie deserves versus the fundamentals — this reference-class check is missing entirely.

85% (67% confidence)

Yes: 85% No: 15%

The best available anchor is Polymarket's 85.5% for the Democrat, and the fundamentals broadly corroborate it: Pappas's ~3.5x cash advantage, a D+6-7 generic ballot with Trump approval near 38%, New Hampshire's Democratic lean in federal races since 2016, and Lean/Tilt-D ratings from all three nonpartisan handicappers. The critique is fair that the August UNH/7NEWS tie (Sununu 45-43) may not yet be fully priced and that the March ratings are stale, but single tied polls three months out in open-seat races historically revert substantially toward fundamentals, and the -4pt 7-day drift suggests the market has already partially absorbed the news. The unresolved GOP primary is roughly neutral-to-favorable for Democrats (a Brown upset would clearly help Pappas), and the fundamentals model's 90-95% argues against pushing below the market. I settle at the anchor, splitting the difference between a possibly-lagging market/stale ratings on one side and an overconfident base-rate model on the other.

Total pipeline time: 184.1s