Kansas Senate race becomes priciest in state history as ad spending tops $84 million

A Kansas Senate race that Republican strategists expected to be an afterthought has become the most expensive in the state's history, with ad spending surging more than 3,300% over the last midterm cycle as both parties pour late money into a contest few predicted would be close.

General-election television and digital ad spending and future reservations in the race between Republican Sen. Roger Marshall and Democratic challenger Adam Hamilton reached $84.5 million as of October 26, according to a tracking report from AdImpact, the ad-tracking firm. That is a 3,332% increase over the 2022 Kansas Senate general election and surpasses the state's previous record of $49.1 million, set in the 2020 Senate race. More than $65.7 million of the total — over three-quarters of it — has been spent in October alone, more than in better-known battlegrounds such as Alaska, New Hampshire or Georgia during the same stretch.

From safe seat to toss-up

The shift in spending has tracked a shift in handicappers' assessments. The Cook Political Report rated the race Solid Republican in July before moving it to Lean Republican and then, this month, to Toss Up, according to AdImpact's analysis. Kansas has not elected a Democrat to the Senate since 1932, a fact widely cited as context for how unexpected the race's competitiveness has become.

Federal Election Commission records confirm both Hamilton's and Marshall's campaign committees as active, federally registered candidates for the seat. Per AdImpact's figures, Hamilton's campaign has spent $15 million on ads to Marshall's $6.3 million, and Democrats have outspent Republicans on the airwaves every week since September 1, with their widest margin — $13.2 million to $7.3 million — coming in the final full week before Election Day. Outside groups account for the bulk of spending on both sides: 81% of Republican ad spending and 66% of Democratic spending has come from super PACs and party committees rather than the campaigns themselves, led by the Senate Leadership Fund on the right and WinSenate on the left.

A costly, negative final stretch

The messaging has grown sharply negative. AdImpact's tracking shows attack ads make up 77% of all broadcast airings in the race, with nearly 90% of outside-group ads featuring negative messaging. Democratic ads have repeatedly attacked Marshall over his vote against releasing files related to Jeffrey Epstein, while Republican ads have sought to cast Hamilton as "too liberal for Kansas." A Newsweek analysis of spending across Senate battlegrounds found Kansas among the handful of states, along with Georgia, where Democrats — not Republicans — have the spending advantage in the race's final two weeks, and described polling there as "neck-and-neck."

AdImpact's broader congressional spending report found that total aired spending across House and Senate races nationally had already topped $3.8 billion by mid-October, outpacing the 2024 cycle's equivalent point by more than $870 million, with Republicans holding an overall spending edge in most competitive Senate races — a pattern Kansas has notably broken.

With Election Day set for November 3, both campaigns are expected to keep spending through the final week in a race that, by AdImpact's count, now ranks among the nation's most expensive — a status almost no one in Kansas politics anticipated when the cycle began.