Kansas has emerged as one of the most unexpected Senate battlegrounds of the 2025-2026 election cycle. Earlier this month, The Cook Political Report moved the Kansas Senate race from Lean R to Toss Up. Last July, the race was rated Solid R. The general election has now seen $84.5M in total ad spending and future reservations, a 3,332% increase over the 2022 Kansas Senate general election. The contest has already surpassed the state’s previous record of $49.1M, set during the 2020 Senate general election, making it the most expensive election in Kansas history.
Democrats Hold Spending Advantage as Both Parties Invest Heavily
In the 2020 Senate general election, Republicans outspent Democrats by $4.5M. This time around, Democratic advertisers hold a $13.0M advantage over Republicans in total ad spending. With Election Day eight days away, Democrats hold $14.2M in future ad reservations, ahead of Republicans’ $8.4M.
Democratic candidate Adam Hamilton’s campaign has spent $15.0M, more than double the $6.3M spent by Republican incumbent Roger Marshall’s campaign. Both candidates have also received significant support from national party committees and PACs. On the Democratic side, the Democratic Senatorial Campaign Committee (DSCC) has spent $1.6M on coordinated advertising with Hamilton, while WinSenate has invested $10.3M. On the Republican side, the National Republican Senatorial Committee (NRSC) has spent $751K on coordinated advertising with Marshall, while Senate Leadership Fund (SLF) has spent $13.1M.
Other outside groups have also entered the fray. Beyond WinSenate, the top Democratic outside groups are People Over Politics ($8.0M), Lower Costs Now ($5.5M), and Government That Works PAC ($4.0M). Excluding SLF, the top Republican groups are Main Street Fund ($4.7M), Plains PAC ($1.8M) and Club for Growth ($1.8M). MAGA Inc.-linked Win It Back PAC spent $1.4M on ads targeting the contest. In total, outside groups account for 81% of Republican ad spending, compared to 66% for Democrats.
Dueling Debuts
Each party’s committees and PACs entered the race within days of their counterparts on the other side. SLF aired its first broadcast ad on 10/3, and a week later, WinSenate aired its first. On 10/15, the DSCC and Hamilton began booking their coordinated ad campaign. A day later, the NRSC and Marshall booked theirs.
Democrats have outspent Republicans every week since 9/1, and their largest advantage is set for the final full week before Election Day, when they’re slated to spend $13.2M to Republicans’ $7.3M.
With both parties’ committees and allied PACs entering the race, spending kicked into high gear in October. More than $65.7M is targeting the contest this month alone, making up more than three-quarters of all spending in the election. That’s more than several other competitive Senate races have seen this month, including Alaska ($50.9M), New Hampshire ($46.4M), Georgia ($43.0M), and North Carolina ($30.2M).
Two Different Conversations on the Airwaves
Republican and Democratic advertisers are focusing on different issues across their broadcast advertising. Democrats’ top messaging themes have been Healthcare, Crime, Epstein, Inflation, and Corruption. Both Hamilton and WinSenate have run ads attacking Marshall for voting against releasing the Epstein files. For Republicans, the top themes are Immigration, Transgender Sports, Agriculture, Healthcare, and Crime. Republican ads have painted Hamilton as “too liberal for Kansas.” In total, Democratic advertisers have run 25.0K broadcast airings, compared to Republicans’ 23.7K. Across both parties, broadcast advertising has been overwhelmingly negative. Attack ads account for 77% of all broadcast airings targeting the election. More than two-thirds of campaign broadcast airings have been negative, while 89% of outside-group airings have featured attack messaging.
In a matter of weeks, Kansas has transformed from a traditionally Republican stronghold into one of the nation's most expensive Senate advertising battlegrounds. With record spending, major investments from national groups, and more than $22M in future reservations, both parties are committing significant resources to the final stretch.
With eight days until Election Day, AdImpact will continue tracking the advertising shaping Kansas and other competitive races across the country.