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535

New Hampshire Senate

  • Chris Pappas (Dem)
  • Scott Brown (Rep)

Favors Dem

Democrats88%

Democrats are favored, winning 88,341 of 100,000 simulated elections.

Favors Dem

Democrats88%

Democrats are favored, winning 88,341 of 100,000 simulated elections.

Forecast detail

as of Oct 4, 2026, 2:30 AM EDT

Estimated margin

D+11.7

5th–95th interval

R+4.5 to D+27.8

Estimated margin

D+11.7

5th–95th interval

R+4.5 to D+27.8

Win probability over time

Dem win probability Rep win probability Tossup band

Polls

The recent polling here measures 2 different matchups, so there is no single contest to average — the forecast rests on fundamentals (the state's partisan lean and the national environment) until the nominees are settled. Every poll is below, grouped by the matchup it tested.

Dem-leaning poll Rep-leaning poll

Polls from partisan-aligned sponsors are shown but not in this view's average — flip “Partisan internals” in the header to include them.Partisan-sponsored polls are in this view's average, shifted 0.7 points toward the non-sponsor party and given half weight — methodology.

Pollster Dates Sample Results Margin House adj. Source
Chris Pappas (D) vs John Sununu (R) · 2 polls Polled before the field was set
Trafalgar Group rep sponsor Sep 26–Sep 27, 2026 1,090 lv Chris Pappas 47.4% Rep 40.5% Other 1.1% D+6.9 — Source
University of New Hampshire Sep 17–Sep 21, 2026 1,392 lv Chris Pappas 50.0% Rep 42.0% Other 2.0% D+8.0 — Source
Chris Pappas (D) vs John Sununu (R) · 21 polls Polled before the field was set
The New York Times/Siena University Sep 15–Sep 22, 2026 613 lv Chris Pappas 49.8% Rep 44.8% D+5.0 D+5.0 Even lean removed Source
InsiderAdvantage Sep 16–Sep 18, 2026 1,200 lv Chris Pappas 48.0% Rep 40.0% D+8.0 D+8.9 R+0.9 lean removed Source
co/efficient Sep 9–Sep 11, 2026 958 lv Chris Pappas 46.0% Rep 46.0% Even D+2.3 R+2.3 lean removed Source
University of New Hampshire Aug 20–Aug 24, 2026 1,846 lv Rep 45.0% Chris Pappas 43.0% R+2.0 — Source
St. Anselm Aug 17–Aug 18, 2026 1,411 lv Chris Pappas 48.0% Rep 41.0% D+7.0 — Source
Peak Insights rep sponsor Jun 24–Jun 27, 2026 500 lv Chris Pappas 43.0% Rep 42.0% D+1.0 — Source
St. Anselm Jun 24–Jun 25, 2026 1,614 rv Chris Pappas 47.0% Rep 41.0% D+6.0 — Source
University of New Hampshire Jun 18–Jun 23, 2026 2,157 lv Chris Pappas 47.0% Rep 44.0% D+3.0 — Source
University of New Hampshire Apr 17–Apr 21, 2026 1,130 lv Chris Pappas 49.0% Rep 42.0% D+7.0 — Source
Emerson College Mar 21–Mar 23, 2026 1,100 lv Chris Pappas 45.4% Rep 43.7% D+1.7 D+1.0 D+0.7 lean removed Source
St. Anselm Mar 16–Mar 18, 2026 1,491 rv Chris Pappas 46.0% Rep 43.0% D+3.0 — Source
yes. every kid. foundation. Jan 28–Jan 29, 2026 563 lv Chris Pappas 45.0% Rep 41.0% D+4.0 — Source
University of New Hampshire Jan 15–Jan 19, 2026 2,038 lv Chris Pappas 50.0% Rep 45.0% D+5.0 — Source
Praecones Analytica Dec 26–Dec 28, 2025 603 rv Chris Pappas 42.3% Rep 35.6% D+6.7 — Source
Guidant Polling and Strategy rep sponsor Dec 9–Dec 11, 2025 600 lv Chris Pappas 47.0% Rep 44.0% D+3.0 — Source
St. Anselm Nov 18–Nov 19, 2025 2,212 rv Chris Pappas 44.0% Rep 41.0% D+3.0 — Source
co/efficient Oct 9–Oct 13, 2025 1,034 lv Chris Pappas 45.0% Rep 42.0% D+3.0 D+5.3 R+2.3 lean removed Source
University of New Hampshire Sep 17–Sep 23, 2025 1,225 lv Chris Pappas 49.0% Rep 43.0% D+6.0 — Source
co/efficient Sep 10–Sep 12, 2025 904 lv Chris Pappas 46.0% Rep 43.0% D+3.0 D+5.3 R+2.3 lean removed Source
1892 Polling rep sponsor Sep 2–Sep 4, 2025 500 lv Chris Pappas 45.0% Rep 43.0% D+2.0 — Source
Quantus Insights rep sponsor Mar 17–Mar 19, 2025 650 rv Rep 53.0% Chris Pappas 44.0% R+9.0 R+7.9 R+1.1 lean removed Source
Aaron Day (I) vs Chris Pappas (D) vs Edmond LaPlante (R) · 1 poll Polled before the field was set
Fabrizio, Lee & Associates rep sponsor Aug 27–Aug 30, 2026 600 lv Chris Pappas 36.0% Ind 1.0% Rep 0.0% D+36.0 — Source
Chris Pappas (D) vs Scott Brown (R) · 15 polls
University of New Hampshire Aug 20–Aug 24, 2026 1,846 lv Chris Pappas 45.0% Scott Brown 40.0% D+5.0 — Source
St. Anselm Aug 17–Aug 18, 2026 1,411 lv Chris Pappas 49.0% Scott Brown 37.0% D+12.0 — Source
St. Anselm Jun 24–Jun 25, 2026 1,614 rv Chris Pappas 48.0% Scott Brown 36.0% D+12.0 — Source
University of New Hampshire Jun 18–Jun 23, 2026 1,980 lv Chris Pappas 52.0% Scott Brown 38.0% D+14.0 — Source
University of New Hampshire Apr 17–Apr 21, 2026 1,115 lv Chris Pappas 52.0% Scott Brown 38.0% D+14.0 — Source
Emerson College Mar 21–Mar 23, 2026 1,100 lv Chris Pappas 47.8% Scott Brown 39.3% D+8.5 D+7.8 D+0.7 lean removed Source
St. Anselm Mar 16–Mar 18, 2026 1,491 rv Chris Pappas 47.0% Scott Brown 38.0% D+9.0 — Source
University of New Hampshire Jan 15–Jan 19, 2026 2,017 lv Chris Pappas 52.0% Scott Brown 42.0% D+10.0 — Source
Praecones Analytica Dec 26–Dec 28, 2025 603 rv Chris Pappas 45.8% Scott Brown 28.0% D+17.8 — Source
Guidant Polling and Strategy rep sponsor Dec 9–Dec 11, 2025 600 lv Chris Pappas 49.0% Scott Brown 38.0% D+11.0 — Source
St. Anselm Nov 18–Nov 19, 2025 2,212 rv Chris Pappas 44.0% Scott Brown 36.0% D+8.0 — Source
co/efficient Oct 9–Oct 13, 2025 1,034 lv Chris Pappas 49.0% Scott Brown 39.0% D+10.0 D+12.3 R+2.3 lean removed Source
University of New Hampshire Sep 17–Sep 23, 2025 1,213 lv Chris Pappas 52.0% Scott Brown 37.0% D+15.0 — Source
co/efficient Sep 10–Sep 12, 2025 904 lv Chris Pappas 50.0% Scott Brown 40.0% D+10.0 D+12.3 R+2.3 lean removed Source
St. Anselm Aug 26–Aug 27, 2025 1,776 rv Chris Pappas 48.0% Scott Brown 37.0% D+11.0 — Source
Chris Pappas (D) vs Dan Innis (R) · 2 polls Polled before the field was set
co/efficient Sep 10–Sep 12, 2025 904 lv Chris Pappas 49.0% Rep 37.0% D+12.0 D+14.3 R+2.3 lean removed Source
St. Anselm Aug 26–Aug 27, 2025 1,776 rv Chris Pappas 48.0% Rep 30.0% D+18.0 — Source
Chris Sununu (R) vs Jeanne Shaheen (D) · 1 poll Polled before the field was set
Praecones Analytica Feb 26–Mar 1, 2025 626 rv Rep 54.4% Dem 45.6% R+8.8 — Source
Jeanne Shaheen (D) vs Scott Brown (R) · 1 poll Polled before the field was set
Praecones Analytica Feb 26–Mar 1, 2025 626 rv Dem 55.1% Scott Brown 44.9% D+10.2 — Source
Frank Edelblut (R) vs Jeanne Shaheen (D) · 1 poll Polled before the field was set
Praecones Analytica Feb 26–Mar 1, 2025 626 rv Dem 58.9% Rep 41.1% D+17.8 — Source

Dispatches about this race

Poll reaction New Hampshire Senate Sep 28, 2026

Trafalgar has Pappas up about seven in New Hampshire, and our forecast stays at 88

The first Trafalgar Group survey in our payload for the open seat lands below our model's average margin but leaves the Democrat's chances where they were this morning.

A Trafalgar Group survey of 1,090 likely voters, fielded September 26-27, puts Democrat Chris Pappas at 47.4% and Republican Scott Brown at 40.5%, with 1.1% choosing another option. That is a Pappas edge of about seven points in that poll.

Our forecast did not move on it. Our model gives Pappas...

Read the full dispatch →

Written autonomously by anthropic/claude-opus-5.5

Poll reaction New Hampshire Senate Sep 24, 2026

UNH puts Pappas at 50 in New Hampshire, and our forecast stays at 87

The University of New Hampshire survey is the third poll in a week to show Chris Pappas ahead, and our model's margin moved by a tenth of a point.

A University of New Hampshire poll of 1,392 likely voters, fielded September 17-21, has Democrat Chris Pappas at 50 percent and the Republican at 42, with 2 percent for another candidate.

Our model gives Pappas an 87 in 100 chance of winning the seat, and Republican Scott Brown a 13 percent...

Read the full dispatch →

Written autonomously by anthropic/claude-opus-5

Poll reaction New Hampshire Senate Sep 24, 2026

NYT/Siena has Pappas up five in New Hampshire, and our forecast holds at 87

The poll's margin is narrower than our projected D+11.6, but the model did not move on it.

A New York Times/Siena University survey of 613 likely voters in New Hampshire, fielded September 15-22, put Democrat Chris Pappas at 49.8% and the Republican at 44.8%, a five-point gap.

Our forecast did not move. We give Pappas an 87 in 100 chance of winning the open New Hampshire Senate seat,...

Read the full dispatch →

Written autonomously by anthropic/claude-opus-5

Poll reaction New Hampshire Senate Sep 18, 2026

InsiderAdvantage has Pappas up eight in New Hampshire, and our forecast stays at 85

The new survey is the first New Hampshire Senate poll since a tied result last week; our model's mean margin moved a tenth of a point.

An InsiderAdvantage survey of 1,200 likely voters in New Hampshire, fielded September 16-18, puts Democrat Chris Pappas at 48 percent and the Republican at 40 percent in the state's open Senate race.

Our model gives Pappas an 85 in 100 chance of winning the seat, against 15 percent for...

Read the full dispatch →

Written autonomously by anthropic/claude-opus-5

Poll reaction New Hampshire Senate Sep 15, 2026

co/efficient poll has New Hampshire Senate tied, and our forecast moves a point

The survey shows Chris Pappas and the Republican line at 46 each; our model now gives Pappas an 84 in 100 chance.

A co/efficient survey of 958 likely voters in New Hampshire, fielded September 9-11, found the Senate race even: Chris Pappas at 46 percent and the Republican line at 46 percent.

Our forecast did not follow the poll. The model now gives Pappas, the Democrat, an 84 in 100 chance of winning the...

Read the full dispatch →

Written autonomously by anthropic/claude-opus-5

Poll reaction New Hampshire Senate Sep 2, 2026

Partisan New Hampshire poll puts Pappas at 36, and our forecast holds at 81

The Fabrizio, Lee survey for the NRSC gives no usable number for Scott Brown, and our model's margin moved a tenth of a point.

One new poll has landed in the New Hampshire Senate race, and it did not move our numbers. Our model gives Chris Pappas, the Democrat, an 81 in 100 chance of winning the open seat, with a mean margin of D+9.9 and a 5th-to-95th-percentile range running from R+8.6 to D+28.4. The previous run, at...

Read the full dispatch →

Written autonomously by anthropic/claude-opus-5

Movement note New Hampshire Senate Aug 31, 2026

New Hampshire Senate eases to 81 for Pappas without new polling

Our estimate of the Democrat's chance fell about 14 points in a week, and the widening of the model's range, not fresh survey data, is what shows up in the numbers.

Our model now gives Chris Pappas an 81 in 100 chance in the New Hampshire Senate race, down from 95% in our run of August 24 at 4:30 p.m. ET. That is a drop of 14.3 points of Democratic win probability over seven days, toward Republican Scott Brown, whose chance we put at 19%.

The mean margin...

Read the full dispatch →

Written autonomously by anthropic/claude-opus-5

Poll reaction New Hampshire Senate Aug 26, 2026

UNH poll shows Pappas up five, and our New Hampshire number eases to 91

The five-point margin is narrower than the last survey here, and our projected margin drops from D+10.8 to D+8.4.

A University of New Hampshire survey of 1,878 likely voters, fielded August 20-24, puts Democrat Chris Pappas at 45 percent and Republican Scott Brown at 40 percent in the race for New Hampshire's open Senate seat.

Our model now gives Pappas a 91 in 100 chance of winning the seat, with a mean...

Read the full dispatch →

Written autonomously by anthropic/claude-opus-5

Poll reaction New Hampshire Senate Aug 20, 2026

New Hampshire poll puts Pappas up 12, and our forecast barely moves

A Saint Anselm College survey of 1,411 likely voters has Chris Pappas at 49% and Scott Brown at 37%; our model now gives Pappas a 95% chance.

A Saint Anselm College survey of 1,411 likely voters, fielded August 17-18, put Democrat Chris Pappas at 49% and Republican Scott Brown at 37% in the race for New Hampshire's open Senate seat.

The number confirmed rather than changed our read. Our model now gives Pappas a 95 in 100 chance of...

Read the full dispatch →

Written autonomously by anthropic/claude-opus-5