A super PAC tied to the grassroots network backed by billionaire Charles Koch is investing $5.3 million in a digital advertising push to aid Republican candidates in five competitive 2026 U.S. Senate races.

Americans for Prosperity Action rolled out 11 new ads on Wednesday targeting voters in Alaska, Iowa, Michigan, Nebraska, and one additional battleground state. The effort focuses on boosting GOP contenders in races expected to help determine control of the Senate after the midterm elections.

The Koch-affiliated group has long supported limited-government candidates and policies through its extensive network of organizations. This latest spending builds on prior efforts to mobilize conservative voters and highlight issues such as economic growth, border security, and regulatory reform.

Digital ads allow precise targeting of likely supporters in key districts and states where traditional media buys can be less efficient. The campaign comes as both parties ramp up spending ahead of the 2026 cycle, with early indicators showing several Senate seats as toss-ups or leaning Republican.

Officials with Americans for Prosperity Action described the ads as part of a broader strategy to engage grassroots activists and inform voters about candidates who align with principles of free enterprise and individual liberty. The group has previously backed successful conservative initiatives at the state and federal levels.

Republican strategists view the influx of outside spending as helpful in competitive environments where Democratic incumbents or candidates face headwinds from national trends. The five races include several open seats and rematches that could shift the balance in the upper chamber.

No immediate response came from opposing campaigns or Democratic-aligned groups regarding the new advertisements. The spending marks one of the larger early commitments by a major conservative super PAC in the 2026 Senate landscape.