A major Republican super PAC plans to spend another $8 million to help Sen. Pete Ricketts (R-Neb.) win reelection, bringing its total investment in the race to $15 million as Republicans face an unexpectedly tight challenge in the traditionally conservative state.

The Senate Leadership Fund, a prominent GOP super PAC, plans to deploy the additional money before Election Day on Nov. 3, according to The Wall Street Journal. The group had already spent $7 million through Cornhusker Majority, an organization whose funding it had not previously disclosed.

The spending reflects Republican concerns about protecting the party’s 53-47 Senate majority amid voter frustration over elevated gasoline and diesel prices and broader economic uncertainty.

Ricketts faces independent challenger Dan Osborn, a former union leader who came within approximately seven percentage points of defeating Republican Sen. Deb Fischer in 2024. President Donald Trump carried Nebraska by 16 points that year, underscoring the unusual political challenge Republicans face in defending the seat.

Trump traveled to Nebraska last week to campaign alongside Ricketts, while Senate Majority Leader John Thune (R-S.D.) is also planning to visit the state to support the incumbent.

Ricketts, a former governor, has sought to portray Osborn as aligned with Democrats while urging Republicans to turn out. Osborn, who led a 2021 strike at Kellogg’s Omaha plant, has emphasized his independent status and a populist economic message aimed at voters dissatisfied with the political establishment.

“This race may determine who is gonna control the U.S. Senate,” Ricketts told supporters at an August campaign event in Lincoln.

The incumbent has also invested heavily in his own reelection effort, contributing $5.25 million of his personal money to his campaign. Ricketts’ campaign had spent nearly $8 million on advertising through Monday, according to AdImpact.

Osborn’s campaign has spent approximately $2.1 million on advertising since the primary, although outside groups have provided additional financial support. Nearly $34 million had already been spent in the race since the primary through Monday, according to the Journal.

The Senate Leadership Fund is not the only outside group preparing to support Ricketts. Politico reported that Fairshake, a major super PAC network backed primarily by cryptocurrency companies Coinbase and Ripple, along with venture capital firm Andreessen Horowitz, also plans to spend in the race. The network has not disclosed the amount it intends to invest.

Ricketts has supported cryptocurrency-friendly legislation as a member of the Senate Banking Committee. Fairshake is also spending to support Republicans in Ohio’s Senate contest.

Although polling has indicated a competitive race, election analysts generally favor Ricketts to retain his seat. The additional spending demonstrates how seriously Republicans are treating the challenge as they attempt to prevent an upset in Nebraska and maintain control of the Senate.