HARRISBURG, Pa. (WHTM) — Celebrity physician turned politician Dr. Mehmet Oz debated his GOP rivals for the first time Monday night in the race to replace retiring Pennsylvania Republican U.S. Sen. Pat Toomey.

In a contest for a seat that could help determine the balance of power in the Senate, Oz and former hedge fund CEO Dave McCormick, both at the top of the GOP primary polls, attacked each other’s records. The Monday evening debate was an opportunity for voters to see how the pair differed on key issues.

For the most part, Oz defended his position as a conservative while McCormick brought up Oz’s past statements on issues to argue he keeps changing his positions.

“The reason Mehmet keeps talking about President Trump’s endorsement is he can’t run on his own positions and his own record,” McCormick said. “The problem, doctor, is there’s no miracle cure for flip-flopping.” 

Earlier this month, Oz earned a critical endorsement from former U.S. President Donald Trump over the other candidates in the race. Trump will be stumping for Oz in Pennsylvania next week.

“President Trump endorsed me,” Oz noted. “The first point he made about why is I’m a conservative, America-first Republican.” 

The other candidates on the debate stage also took their turns throwing jabs at Oz as well as each other. The Hill’s Tal Axelrod broke down the debate’s key moments here. The primetime event was produced by ABC27 in Harrisburg and Nexstar Media.

Oz, who has spent years as one of America’s most popular daytime television show hosts, made the jump into politics at the end 2021 after the GOP frontrunner in the Senate race suspended his campaign due to personal and legal issues.

In an early April poll, McCormick had the support of 18% of likely GOP voters while Oz was right behind him at 17%. Political commentator Kathy Barnette finished third with 10% in the WHTM/Emerson College Polling/The Hill Pennsylvania primary poll. They were followed by businessman Jeff Bartos at 9% and former U.S. Ambassador Carla Sands at 8%.

The primary election for U.S. senator from Pennsylvania is scheduled to take place on May 17. Voters must register to vote by May 2.