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Forecast6 days out
← SenateNovember 3, 2026

Kansas · U.S. Senate

Roger Marshall is slightly favored to hold Kansas’s Senate seat. Predicted margin: R+1.9.

Adam Hamilton (D)37 in 10046.843.1–50.6
Roger Marshall incumbent (R)63 in 10048.744.9–52.5

Under each share, its likely range (80 in 100 simulations) · * incumbent

Tilt RRepublican-held seat

Forecast history

Steady-0.1 pts · Oct 26 → Oct 28Kansas U.S. Senate: steady — the published margin moved -0.1 points between the Oct 26 and Oct 28 editions (3 of 23 stored editions). This is movement of the published forecast between editions.
EVENR+5R+10Aug 1Nov 3 · Election Day

Latest reading · Oct 28 · first published Oct 6 · 80% range · margin points R+9.4 to D+5.7. Methodology

 

About this series

Reconstructed with the current model Aug 1 – Oct 5; published readings Oct 6 – Oct 28. Each reconstructed day is the current model on that day’s own inputs, not a forecast published then. Corrections are dated in the changelog.

Faded: CTMM 2.2 reconstructed history: computed after the fact with each date's available polls and environment, without expert ratings; not an issued forecast. Issued forecasts begin at the launch marker.

CTMM 2.2 readings for 2026-09-16, 2026-09-17, 2026-09-18 were computed after the fact with each day's available inputs: no edition was issued on those days. Not an issued forecast.

Data table
DateMarginChance80% rangeReading
Oct 28R+1.9R win 63.2%R+9.4 to D+5.7Published forecast
Oct 27R+1.9R win 63.5%R+9.5 to D+5.6Published forecast
Oct 26R+1.7R win 62.2%R+9.4 to D+5.9Published forecast
Oct 25R+1.8R win 62.4%R+9.4 to D+5.8Published forecast
Oct 24R+1.8R win 62.7%R+9.4 to D+5.8Published forecast
Oct 23R+1.8R win 62.8%R+9.4 to D+5.7Published forecast
Oct 22R+1.9R win 63.1%R+9.4 to D+5.7Published forecast
Oct 21R+1.9R win 63.3%R+9.4 to D+5.6Published forecast
Oct 20R+1.7R win 62.3%R+9.2 to D+5.7Published forecast
Oct 19R+1.8R win 62.6%R+9.2 to D+5.7Published forecast
Oct 18R+1.8R win 62.8%R+9.2 to D+5.6Published forecast
Oct 17R+1.8R win 63.0%R+9.3 to D+5.6Published forecast
Oct 16R+1.9R win 63.3%R+9.3 to D+5.6Published forecast
Oct 15R+1.7R win 62.3%R+9.2 to D+5.7Published forecast
Oct 14R+1.8R win 62.5%R+9.2 to D+5.7Published forecast
Oct 13R+1.8R win 62.7%R+9.2 to D+5.7Published forecast
Oct 12R+1.8R win 62.9%R+9.3 to D+5.6Published forecast
Oct 11R+1.9R win 63.5%R+9.5 to D+5.6Published forecast
Oct 10R+2.0R win 63.8%R+9.5 to D+5.6Published forecast
Oct 9R+2.0R win 64.1%R+9.5 to D+5.5Published forecast
Oct 8R+2.0R win 64.4%R+9.5 to D+5.4Published forecast
Oct 7R+2.1R win 64.7%R+9.5 to D+5.4Published forecast
Oct 6R+3.1R win 70.1%R+11.1 to D+4.8Published forecast
Oct 5R+3.2R win 70.3%R+11.1 to D+4.8Recomputed with the current model
Oct 4R+3.2R win 70.5%R+11.1 to D+4.7Recomputed with the current model
Oct 3R+3.2R win 70.8%R+11.1 to D+4.7Recomputed with the current model
Oct 2R+3.4R win 70.6%R+11.7 to D+5.0Recomputed with the current model
Oct 1R+3.8R win 72.4%R+12.2 to D+4.7Recomputed with the current model
Sep 30R+3.8R win 72.7%R+12.3 to D+4.7Recomputed with the current model
Sep 29R+3.8R win 72.8%R+12.3 to D+4.6Recomputed with the current model
Sep 28R+3.9R win 73.1%R+12.3 to D+4.5Recomputed with the current model
Sep 27R+3.9R win 73.3%R+12.3 to D+4.5Recomputed with the current model
Sep 26R+3.9R win 73.5%R+12.3 to D+4.4Recomputed with the current model
Sep 25R+4.0R win 73.8%R+12.3 to D+4.4Recomputed with the current model
Sep 24R+4.0R win 74.0%R+12.4 to D+4.3Recomputed with the current model
Sep 23R+5.1R win 78.0%R+13.9 to D+3.7Recomputed with the current model
Sep 22R+5.2R win 78.3%R+14.0 to D+3.6Recomputed with the current model
Sep 21R+5.2R win 78.5%R+14.0 to D+3.6Recomputed with the current model
Sep 20R+5.2R win 78.6%R+14.0 to D+3.5Recomputed with the current model
Sep 19R+5.3R win 78.8%R+14.0 to D+3.5Recomputed with the current model
Sep 18R+5.3R win 78.9%R+14.0 to D+3.4Reconstructed with the stated inputs
Sep 17R+7.6R win 85.5%R+17.1 to D+1.8Reconstructed with the stated inputs
Sep 16R+7.7R win 85.6%R+17.1 to D+1.7Reconstructed with the stated inputs
Sep 15R+7.7R win 85.8%R+17.1 to D+1.7Recomputed with the current model
Sep 14R+7.7R win 85.9%R+17.1 to D+1.6Recomputed with the current model
Sep 13R+7.8R win 86.0%R+17.1 to D+1.6Recomputed with the current model
Sep 12R+7.8R win 86.1%R+17.1 to D+1.5Recomputed with the current model
Sep 11R+7.8R win 86.3%R+17.1 to D+1.5Recomputed with the current model
Sep 10R+8.7R win 85.4%R+19.6 to D+2.1Recomputed with the current model
Sep 9R+8.8R win 85.5%R+19.6 to D+2.1Recomputed with the current model
Sep 8R+8.8R win 85.6%R+19.6 to D+2.0Reconstructed with the stated inputs
Sep 7R+8.9R win 85.8%R+19.7 to D+1.9Reconstructed with the stated inputs
Sep 6R+8.9R win 85.8%R+19.6 to D+1.9Reconstructed with the stated inputs
Sep 5R+8.9R win 85.8%R+19.6 to D+1.9Reconstructed with the stated inputs
Sep 4R+8.9R win 85.9%R+19.7 to D+1.9Reconstructed with the stated inputs
Sep 3R+8.9R win 85.9%R+19.6 to D+1.9Reconstructed with the stated inputs
Sep 2R+10.5R win 88.8%R+21.5 to D+0.6Reconstructed with the stated inputs
Sep 1R+10.4R win 88.7%R+21.5 to D+0.7Reconstructed with the stated inputs
Aug 31R+10.4R win 88.7%R+21.5 to D+0.7Reconstructed with the stated inputs
Aug 30R+10.4R win 88.7%R+21.5 to D+0.7Reconstructed with the stated inputs
Aug 29R+10.4R win 88.6%R+21.4 to D+0.7Reconstructed with the stated inputs
Aug 28R+10.4R win 88.7%R+21.5 to D+0.7Reconstructed with the stated inputs
Aug 27R+10.4R win 88.7%R+21.4 to D+0.7Reconstructed with the stated inputs
Aug 26R+10.4R win 88.8%R+21.5 to D+0.6Reconstructed with the stated inputs
Aug 25R+10.4R win 88.8%R+21.4 to D+0.6Reconstructed with the stated inputs
Aug 24R+10.4R win 88.8%R+21.4 to D+0.6Reconstructed with the stated inputs
Aug 23R+10.4R win 88.8%R+21.4 to D+0.6Reconstructed with the stated inputs
Aug 22R+10.5R win 88.6%R+21.7 to D+0.7Reconstructed with the stated inputs
Aug 21R+10.5R win 88.7%R+21.7 to D+0.7Reconstructed with the stated inputs
Aug 20R+10.5R win 88.7%R+21.7 to D+0.7Reconstructed with the stated inputs
Aug 19R+10.5R win 88.6%R+21.6 to D+0.7Reconstructed with the stated inputs
Aug 18R+10.4R win 88.6%R+21.6 to D+0.7Reconstructed with the stated inputs
Aug 17R+10.5R win 88.7%R+21.6 to D+0.7Reconstructed with the stated inputs
Aug 16R+10.5R win 88.7%R+21.6 to D+0.7Reconstructed with the stated inputs
Aug 15R+10.4R win 88.6%R+21.6 to D+0.7Reconstructed with the stated inputs
Aug 14R+10.5R win 88.8%R+21.6 to D+0.6Reconstructed with the stated inputs
Aug 13R+11.9R win 90.6%R+23.5 to R+0.4Reconstructed with the stated inputs
Aug 12R+11.9R win 90.5%R+23.4 to R+0.3Reconstructed with the stated inputs
Aug 11R+11.9R win 90.6%R+23.5 to R+0.3Reconstructed with the stated inputs
Aug 10R+11.9R win 90.6%R+23.4 to R+0.3Reconstructed with the stated inputs
Aug 9R+11.9R win 90.6%R+23.4 to R+0.3Reconstructed with the stated inputs
Aug 8R+11.9R win 90.6%R+23.4 to R+0.3Reconstructed with the stated inputs
Aug 7R+11.9R win 90.6%R+23.4 to R+0.3Reconstructed with the stated inputs
Aug 6R+12.9R win 91.4%R+24.9 to R+0.9Reconstructed with the stated inputs
Aug 5R+12.9R win 91.4%R+24.9 to R+0.9Reconstructed with the stated inputs
Aug 4R+12.9R win 91.4%R+24.9 to R+0.9Reconstructed with the stated inputs
Aug 3R+12.9R win 91.4%R+24.9 to R+0.9Reconstructed with the stated inputs
Aug 2R+13.0R win 91.5%R+25.0 to R+0.9Reconstructed with the stated inputs
Aug 1R+12.9R win 91.4%R+25.0 to R+0.9Reconstructed with the stated inputs

The polls

Poll average D+0.2A poll’s weight halves every 60 days and grows with its sample. Each pollster counts once, at its best release. Every poll counts at its published margin, sponsored or not.In Senate races the forecast then counts a poll sponsored by a party or campaign at a quarter of its weight and moves its margin 2 points against that party, which puts the average it reads at R+0.1. It then applies a fitted correction of 1.6 points toward Republicans for Senate races, measured from past polling error, before blending it with its other evidence.14 recorded polls · 14 in the poll average

FieldworkAddedPollsterResultSample
from 2026-10-202d agoRedBox Research (D) ↗R+1.0D 45% · R 46%1,301 LV
from 2026-10-13InsiderAdvantage ↗R+1.1D 46.6% · R 47.7%1,200 LV
from 2026-10-09InsiderAdvantage ↗D+0.8D 47.5% · R 46.7%1,200 LV
from 2026-09-30GBAO ↗D+5.0D 49% · R 44%600 LV
from 2026-09-24YouGov ↗D+3.0D 48% · R 45%2,253 LV
from 2026-09-29Trafalgar Group ↗D+0.9D 44.4% · R 43.5%1,095 LV
from 2026-09-15Emerson College ↗NexstarD+1.4D 44.75% · R 43.3%750 LV
from 2026-09-08co/efficient ↗R+5.0D 44% · R 49%915 LV
Explore each poll’s weight in the average

8 of 14 matching · 14 total

Poll average D+0.2

RedBox Research (D)23 Oct · 1,301 LV · added 26 Oct
InsiderAdvantage14 Oct · 1,200 LV · added 16 Oct
InsiderAdvantage10 Oct · 1,200 LV · added 12 Oct
GBAO4 Oct · 600 LV · added 7 Oct
YouGov4 Oct · 2,253 LV · added 7 Oct
Trafalgar Group1 Oct · 1,095 LV · added 5 Oct
The New York Times/Siena University30 Sep · 605 LV · added 3 Oct
Emerson College16 Sep · 750 LV · added 5 Oct
Explore all 14 polls for this race

How the margin was built

Tap an input for its calculation and source.

Toward D+14.4
Toward R−16.3
Forecast marginR+1.9

Displayed values are rounded.

All calculations & sources

How this state voted, 2024 −16.120 points

The state's presidential margin in 2024 as a share of all votes cast, from our own county sums — the same measurement the model's statewide terrain center is built from. Every pull below is measured from here, not from EVEN, which is why a landslide seat's listed pulls are small numbers and still land where the forecast does.

  • 2024 presidential result for this state, as a share of all votes cast, from Call the Map's own county sums.
  • Same source as Act I's 2024-president reference mark, so the origin lands on it.

This race’s polls +8.245 points

What this race’s own recent polling adds beyond its prior. The forecast weights each poll for recency and sample size and counts each pollster once; the weights listed here are those of the polls’ own average.

  • RedBox Research (D) (2026-10-23, n=1,301): R+1.0 · weight 0.93 in the poll average
  • InsiderAdvantage (2026-10-14, n=1,200): R+1.1 · weight 0.80 in the poll average
  • InsiderAdvantage (2026-10-10, n=1,200): D+0.8 · weight 0.77 in the poll average
  • GBAO (2026-10-04, n=600): D+5.0 · weight 0.51 in the poll average
  • YouGov (2026-10-04, n=2,253): D+3.0 · weight 0.76 in the poll average
  • Trafalgar Group (2026-10-01, n=1,095): D+0.9 · weight 0.66 in the poll average
  • … and 8 more below.
  • Poll average D+0.2, from 14 polls · 14 recorded polls. This is the polls’ own average, each poll at its published margin, the figure this page’s poll summary shows. In Senate races the forecast then counts a poll sponsored by a party or campaign at a quarter of its weight and moves its margin 2 points against that party, which puts the average it reads at R+0.1. It then applies a fitted correction of 1.6 points toward Republicans for Senate races, measured from past polling error, before blending it with its other evidence. The forecast gives the polls 98% of the weight against its structural prior for this race, which moves the margin 8.2 points away from Republicans from where it stood before the polls. Eligible polls: latest poll: 2026-10-23 (5 days old).

National environment +3.187 points

The contribution to this race’s margin, not the national polling margin itself. The race’s loading, reference level and polling blend determine how much of the national climate reaches its final forecast.

  • Three-source blend, updated 2026-10-14: 53% generic-ballot aggregates (D+7.7) · 28% special-election overperformance (D+9.0 across 46 specials) · 20% approval-implied (D+9.1 from net approval -24.3).
  • Latest polls — generic ballot 2026-10-14 (14 days old), approval 2026-10-14 (14 days old).
  • Generic-ballot average D+7.7 · support factor 0.87 (the share of that channel's capacity the admitted polls carry) — separate inputs; their product is a capacity diagnostic, not a margin.
  • Weights are the 55/25/20 capacities scaled by each channel's evidence and renormalized, so thin polling widens the interval instead of pulling the center toward zero — 12% of the weight is carried that way.
  • Blended national environment: D+8.3.
  • Applied at full strength to this chamber's races.
  • This step’s recorded contribution to the margin is +3.2 D.
  • Blended national environment: D+8.3 (updated 2026-10-14).
  • Effective poll weight 88%; fundamentals share 12%, carried by the interval (×1.06) rather than by the center.
  • The support factor is the share of the generic-ballot capacity the admitted polls carry; average × support is a capacity diagnostic, not a margin, and is not what the row above multiplies.
  • Applied at full strength to this chamber: +3.2 of this margin.

Fitted model, above the terrain shown +2.850 points

What the fitted model adds on top of the starting terrain above — incumbency, past results, campaign finance and the other fitted terms — measured from that terrain rather than from EVEN. It is a comparison with the starting point already shown, not a separate input. The source detail lists the variables the fit uses.

  • Fitted baseline -13.270 minus starting point -16.120 = 2.850 points.
  • For orientation, the presidential results here: 2024 R+16.1, 2020 R+14.8.
  • The work: the −13.3 D fundamentals push is the sum of the dynamic formula's surviving variables for this race — each one's own contribution is listed below.
  • fundamentals core = 25-term dynamic formula (mass fit over the master feature matrix, held-out-cycle validated; see matrix/feature_dictionary.md + mass_fit_report.json)
  • 9-term formula, held-out validated.

Structural safeguards −0.144 points

Bounded corrections that keep the model consistent with structural facts.

  • Applied only when a safe state's dynamic fundamentals point in the same direction as its strong presidential lean but are materially compressed toward zero.
  • The 25% correction toward that lean improved safe-race MAE in strict expanding-window validation without changing a historical call.
  • The disclosed adjustment is −0.1 D.

Votes for other candidates +0.088 points

Every step above is measured between the two major-party candidates alone, as if nobody else were on the ballot. The forecast sets 4.5% of the vote aside for other candidates and write-ins, so as a share of every vote cast the gap between the two is smaller by that much. This step is exactly that: the two-party margin times the share going to other candidates. It is the same arithmetic that turns the two-party margin into the two shares printed at the top of the page.

The components this edition publishes for this race, in points. “Other factors” closes the sum to the two-party structural lean exactly. The margin the page prints is a share of every vote cast, so the “Votes for other candidates” row carries the exact difference between the two-party lean and that margin; with it, the walk sums to the printed margin exactly.

Named factorContribution
FundamentalsThe admitted fitted baseline. Its surviving variables differ by office; the source detail above identifies those used for this race.−13.27
This race's pollsAdmitted head-to-head polls of this race, recency- and quality-weighted.+8.25
National environmentThe national environment’s contribution to the prior. Polling can attenuate its influence; this value is not the national polling margin.+3.19
Structural terrain safeguardA bounded pull toward presidential terrain in heavily partisan states.−0.14
Other factors+0.00

Where the votes are

The map of this race loads here.

Recent elections

ElectionResultVotes cast
2020 · U.S. Senate ↗R+11.41,367,755
2014 · U.S. Senate ↗Not a D–R contestThe ballot was not a Democrat versus a Republican; a D/R margin cannot identify the winner.866,191
2008 · U.S. Senate ↗R+23.61,210,690
2002 · U.S. Senate ↗Not a D–R contestThe ballot was not a Democrat versus a Republican; a D/R margin cannot identify the winner.776,850

Margins are the Democrat’s share of all votes cast minus the Republican’s.

The money

The tick marks cash on hand. A missing filing stays blank rather than becoming $0.

One more fundraising reportCall the Map · $325

The candidates are comfortably out-fundraising the website covering them. A little rude, perhaps, but statistically unsurprising.

Received so far
$325
Measured compute
$26,188.58

Ko-fi and Buy Me a Coffee supports are counted as each one arrives. Measured compute prices model runs at standard published API rates; it is not what I paid. Hosting, data and subscriptions, the domain and my own time are not counted. Donations buy gratitude, never a forecast adjustment.

Supporters are listed by first name and last initial; a username alone is shortened to its first eight characters. Want your full name shown? Say so in your message. Give privately, or leave the name blank, and you are listed as Anonymous, with the platform and date. Supporters who give a name may also be thanked by name in the newsletter.

Thank you to Tom H., ColoradoFlyer, Chris, EW, gbaileym…, True Independent, MT V., JBL, Erin G., Caroline M., Melanie, MKV and 7 more.

See the public support ledger →

Outside spending

Separate from what the campaigns raised

For and against Adam Hamilton$9.3M

10 spending groups
GroupForAgainst
SLF PAC$0$2.5M
MAIN STREET FUND$0$2.4M
Club for Growth Action$0$1.3M
Americans for Prosperity Action, Inc. (AFP Action) DBA CVA Action and DBA LIBRE Action$0$1.0M
UNITED FUTURES PAC$622K$0
Win it Back PAC$0$520K
AB PAC$414K$0
Lower Costs Now$272K$0
Fund for a Working Congress$0$184K
Somos PAC$133K$0

For and against Roger Marshall$11.9M

11 spending groups
GroupForAgainst
PEOPLE OVER POLITICS ACTION FUND$0$6.6M
WinSenate$0$2.0M
Lower Costs Now$0$1.1M
Americans for Prosperity Action, Inc. (AFP Action) DBA CVA Action and DBA LIBRE Action$1.0M$0
THE 1861 INITIATIVE$0$600K
SENATE CONSERVATIVES FUND$244K$0
Protect Freedom Political Action Committee$200K$0
UNITED FUTURES PAC$0$88K
SENATE CONSERVATIVES ACTION$46K$0
UNITED FUTURES$0$25K
NATIONAL RIFLE ASSOCIATION OF AMERICA POLITICAL VICTORY FUND$4K$0

Includes primary spending. Opposition is recorded against its named target; no benefit to another candidate is assumed.

$2.3M in outside spending on earlier candidates.

FEC filings · through 07/15/2026 · Definitions & method

Race context

Turnout, 2018 midterm
49.8% 1,060,000 ballots
Turnout, 2022 midterm
47.6% 1,008,998 ballots
2024 presidential margin
R+16.4between the two parties

Turnout is ballots cast statewide as a share of the voting-eligible population. Source: University of Florida Election Lab ↗

Population profile

White alone · 79.8%2,341,473 of 2,935,922 · Residents2022 Census · matched race geography

Coverage

1 story · 10 quotes

All coverage and full posts on the Wire →

Forecast as of October 28, 2026: Call the Map currently has Roger Marshall ahead of Adam Hamilton by R+1.9, with a 63 in 100 chance to win. The seat is currently held by a Republican. That result would keep the seat with Republicans. The current poll average is D+0.2; 14 public polls are recorded.