Sen. Roger Marshall, R-Kan., says he understands he is in a fight for his political survival, even in a state where no Democrat has won a Senate seat since the Great Depression. The race was not on national Republicans' radar until a few months ago, but it has since moved into toss-up territory.

The change came with the rise of Adam Hamilton, a well-known megachurch pastor who presents himself as a moderate. In an interview with Fox News Digital in Wichita, held hours before President Donald Trump was scheduled to rally for the incumbent, Marshall conceded that a loss could cost his party the chamber.

"I'm not a political expert, I'm a physician, but if we lose Kansas, I don't see how we keep control of the Senate," Marshall said. He added that a vote for Hamilton is "a vote for Chuck Schumer and Democrat control of the Senate." Republicans currently hold a 53-seat majority and are hoping to preserve or expand it.

Political scientists say Hamilton is an unusual candidate. He has been a prominent figure in Kansas for roughly three decades as leader of the Church of the Resurrection. Don Haider-Markel, a political science professor at the University of Kansas, said he could not imagine conditions being much better for Democrats this cycle. He noted that the last time a Senate race looked close was 2020, and it ended up less competitive than expected. Marshall won that race, his first for the Senate, by nearly 12 points with Trump at the top of the ticket.

This year Trump is not on the ballot, and midterm elections often act as a check on the party in power. At his rally in Park City, Kansas, the president asked supporters to set that aside. "In this election, I'm asking you to pretend please that I'm on the ballot," Trump said. "Just pretend."

Marshall pointed to the cost of fuel as a major reason for the tightening race. He said he visits all 105 Kansas counties each year and finished that circuit in June, hearing more frustration as prices climbed. He estimated he led by 12 points before the Iran War, and that his polling fell as prices rose. Along the roads linking Hamilton's home base of Overland Park to Wichita, gas station signs showed gasoline just under $4 and diesel well above $6.

Nathaniel Birkhead, a political science professor at Kansas State University, said fuel costs were one factor but not the only one. He argued that Marshall's close association with Trump, at a time when the "Trump Brand is not particularly popular," gave Hamilton an opening. He said Marshall is tying himself to Trump instead of separating from him, and suggested the contest would be far less competitive if Sen. Jerry Moran were the nominee.

That leaves Republicans balancing two needs: energizing Trump's loyal base while not alienating other Republicans and independents who might stay home or back the Democrat. Marshall said he cannot win without Trump voters turning out, and that most undecided voters are Trump supporters who need to hear a plan from the president on bringing prices down. In his view, if Democrats stay in control, gas prices will never fall.