Who Will Win the 2026 Kansas Senate Election? Polls and Latest News

Live market odds

Which party will win the 2026 US Senate election in Kansas?

Each outcome's chance, from what traders are paying right now on .

Compare every venueCents per $1 payout, before fees

Consensus prediction market price

Since the first article's chart, October 26 to today

Hover the chart for prices over time. Each dot under it is a story update; hover to preview it, click to jump to it.

Background

Kansas voters decide on Nov. 3, 2026 which party wins the state's US Senate seat. Republican incumbent Roger Marshall faces Democrat Adam Hamilton, with a Libertarian candidate also on the ballot. The market on which party wins is set to resolve by Nov. 17.

The question is settled in a single general election, so the party that finishes first takes the seat. The fundamentals favor Republicans: Trump carried Kansas by 16 points in 2024, and Democrats have not won a Kansas Senate seat since 1932. Still, public polls disagree, and forecasters such as Cook Political Report and Decision Desk HQ rate the race a toss-up.

Public polls, newest first. Bases differ, so compare like with like.
Poll	Fieldwork	Base	Adam Hamilton	Roger Marshall
Emerson College	Oct. 26-28	All respondents	49%	45%
Washington Post/Schar School	Oct. 22-26	All respondents	52%	43%
CNN/SSRS	Oct. 20-26	Likely voters	49%	45%
RedBox Research	Oct. 20-23	All respondents	45%	45.7%

Oct. 31, 2026: Adam Hamilton Hits 51% as Post Poll Shows Him Up 9 on Marshall

The latest Adam Hamilton vs. Roger Marshall polls show the Democrat ahead, and his price in the "Which party will win the 2026 US Senate election in Kansas?" market rose to 51%. A Washington Post/Schar School poll released Oct. 30 had Hamilton leading the Republican incumbent 52% to 43%, outside its 3.9-point margin of error, according to USA Today. Emerson and CNN/SSRS polls show a narrower 4-point Hamilton lead, and forecasters still rate the Nov. 3 race a toss-up.

Adam Hamilton's Senate Chances Rise to 51% After Washington Post Poll Shows Him Leading Roger Marshall

In that market, Hamilton's implied probability climbed from 41% to 51% on Oct. 31, about 10 percentage points in three days. The gain coincides with the Post poll's release. Prices across venues are tightly aligned: 50% on Kalshi, 52% on Polymarket and 51% on PredictIt.

The Post survey (Oct. 22-26, 801 respondents) was the first to show Hamilton clearly ahead rather than in a close race. "If this poll was done correctly, these results are pretty startling," Emporia State political scientist Michael Smith told KWCH. Emerson's final poll (Oct. 26-28, n=800) had Hamilton up 49-45, with a Libertarian near 3%. CNN/SSRS (Oct. 20-27) found the same 49-45 margin, according to The Hill.

Why the 9-Point Hamilton Lead Is Treated With Caution

The Post's 9-point margin is more than double the Emerson and CNN/SSRS leads. The Post's pollsters noted that Democrats were overrepresented in the sample, which tilts the headline result toward Hamilton. A RedBox Research poll (Oct. 20-23), sponsored by a pro-GOP super PAC, had the race essentially tied, 45.7% Marshall to 45.0% Hamilton.

Models and ratings have not followed the market. The Hill/Decision Desk HQ and Cook Political Report rate Kansas a toss-up, and DDHQ's model gives Marshall a 53% to 58% chance, so the model still favors the incumbent while traders now lean slightly toward Hamilton. The fundamentals also run against the Democrat: Trump carried Kansas by 16 points in 2024, and Democrats have not won a Kansas Senate seat since 1932. Polling averages put Hamilton's lead at roughly 3 to 4 points as of Oct. 30.

What Could Confirm or Reverse Hamilton's 51%

Trump's Salina rally for Marshall, reported by KWCH, is the latest Republican push to close the gap. Any further public polls before Nov. 3 will test whether the Post result is an outlier or confirmation, and a shift in Cook's rating or DDHQ's model toward Hamilton would back the market's lean. The election on Nov. 3 settles the question, with the market resolving by Nov. 17. Live pricing is on the Kansas Senate race market page.

Earlier Updates

Oct. 29, 2026: Kansas Senate Polls: Marshall Falls to 52% After CNN Poll

Roger Marshall (R)61% → 52%▼9

On Oct. 29, a CNN/SSRS poll showed Democrat Adam Hamilton at 49% to Republican Roger Marshall's 45% among 838 likely Kansas voters, with a 4.5-point margin of error. Action Network reported that Polymarket reclassified the race from Lean R to Tossup, and the Sunflower State Journal reported the poll results.