During the interview Hannity asked Oz some softball questions about why he was running and how he would respond to the criticism that he is new to the state. He then offered him a chance to assuage the concerns of conservatives who might doubt that he is one of them.

“I say I'm a conservative. I used to say I'm a Reagan conservative. I would say I'm an America First, Make America Great Again conservative,” Hannity said. “How would you describe, in just a sentence, your political ideology, philosophy? You are running as -- in a Republican primary. How would you sum it up?”

Oz replied, “I match yours.”

Oz used subsequent appearances on Hannity’s Fox show to push back against criticisms that he is insufficiently conservatives, lash out at right-wing targets like Dr. Anthony Fauci, and denounce President Joe Biden for firing him from the presidential fitness council.

Hannity has formally endorsed Oz’s campaign. While introducing him for a March 3 interview on his radio show, Hannity said: “I'm supporting his nomination to be the Republican candidate. I've known him for many, many years. Some people said, ‘How do I know he's a conservative, Hannity?’ I got the same questions about Donald Trump, and I think I was proven right.” On Fox, Hannity likewise said on March 23 that Oz will “make a great senator. I've known him for years. He is a solid America First, Make America Great Again conservative. That's why I'm supporting him, and a friend.”

Oz prominently displays Hannity’s support on his campaign website’s endorsements page.

Hannity’s role at Fox ensures Oz’s access to a large audience of Republican base voters — but his sidegig as a GOP political operative may have been even more valuable to Oz’s campaign. He spent the Trump administration moonlighting as one of the president’s most trusted advisers and reportedly used that influence on Oz’s behalf. Other key Trump allies denounced Oz as a latecomer to the movement and many conservative luminaries backed McCormick. But Hannity reportedly “actively lobbied for Trump to endorse the celebrity doctor” and his recommendation “played an outsized role in influencing Trump’s decision” to do so in an April 9 statement.

Two nights later on Fox, Hannity sought to lessen the blowback from Trump’s endorsement. “Dr. Oz is the America First candidate and running in Pennsylvania, which is why I have endorsed him,” Hannity said while introducing the candidate for yet another interview. “He's fully behind the America First, Make America Great Again agenda, strong on the border, strong on energy independence, tough on crime, believes in law and order, supports the right to life, he follows the science on COVID, wants to fire Fauci.”

But the next night on her own Fox show, Ingraham joined the critics of Trump’s endorsement — and highlighted Hannity’s influence on the decision.

After playing a video of Oz making comments about climate change, guns, and abortion that are anathema to conservatives, Ingraham asked her guest, former Trump White House official Kellyanne Conway, whether Trump had erred. When Conway refused to give a straight answer, Ingraham said, “Hannity, I think, I believe, endorsed Oz and … that’s probably not inconsequential for President Trump” before adding, “I think it was a mistake to endorse Oz. I'll say it. I'm not afraid to say it. It was a mistake to endorse Oz.”

While Ingraham has not formally endorsed Oz’s primary opponent McCormick, she has repeatedly offered him a platform and praised his background.

“All eyes are on the top two candidates, one of them served in the Turkish military, Dr. Oz, everyone knows him from TV,” she said while introducing McCormick for a February 22 interview. “And the other went to West Point and served as an Army Ranger in the Gulf War.”

McCormick received an opportunity to pitch his candidacy to Ingraham’s viewers and respond to criticism that he won’t be “tough on China” like Trump. His answers apparently satisfied her concerns. “You clarified a lot, Dave, tonight, and we really appreciate your joining us,” she said at the end of the interview.

Ingraham used subsequent interviews with McCormick to give him a chance to push back against Oz’s attacks on his position on tariffs with China and to levy his own salvos at Oz’s past statements on abortion.

She isn’t the only one at Fox who seems to prefer McCormick. Host Mark Levin told him he would make “an excellent senator” during an interview, while contributors Mike Huckabee and Mike Pompeo have endorsed and campaigned for him.

Fox will win the primary no matter which Republican emerges from the May 17 election, but it remains to be seen which Fox host has more sway with GOP voters in Pennsylvania.