Fox News’ role as an appendage of the Republican Party has made the network a battlefield for the U.S. Senate primary in Pennsylvania as two of its prime-time hosts rally behind different candidates. 

Sean Hannity is supporting Dr. Mehmet Oz, a heart surgeon and TV personality notorious for promoting pseudoscience and medical misinformation. Hannity has hosted 19 of the 25 Fox weekday interviews Oz has done since declaring his candidacy, and he regularly invites him on his nationally syndicated radio show. He has vouched for Oz’s political bona fides, publicly endorsed him on his TV and radio shows, and used his influence with Donald Trump to secure the former president’s coveted support. 

Laura Ingraham, meanwhile, appears to favor Dave McCormick, a former hedge fund CEO and Bush administration official. She has given McCormick 3 of his 9 total Fox weekday interviews during the primary and criticized Trump and Hannity for backing Oz.

Hannity and Ingraham are both GOP kingmakers, and their shows are among the party’s most influential platforms. Their colleague Tucker Carlson, meanwhile, has ignored the Pennsylvania race altogether as he focused on helping J.D. Vance to victory in the Ohio Senate primary.

Oz, who entered the public consciousness through broadcast TV as a guest on The Oprah Winfrey Show and on his own eponymous program, used regular appearances on Fox to rebrand as a right-wing commentator, much as Trump himself did a decade ago. Oz has appeared on Fox weekday programs at least 130 times since September 2017, according to the Media Matters guest database, including 75 interviews on Fox & Friends and 38 on Hannity. 

Oz became a fixture on the network during the early days of the COVID-19 pandemic, which helped him cement his relationships with Hannity and Trump. The Fox host regularly hosted Oz for interviews on his TV and radio shows and repeatedly stressed that the two stay up talking until 2 o’clock or “3 in the morning now, late at night.” Oz’s Fox appearances attracted the Fox-obsessed president’s attention, particularly his constant support for the use of the anti-malarial drug hydroxychloroquine as treatment (studies show this drug is not effective). In response, Trump urged his administration officials to consult with Oz on their handling of COVID-19.

Those relationships proved crucial to Oz’s Senate run. As a first-time candidate with a long history of statements unpopular with his party’s base, Oz has benefited from the public approval of Hannity and Trump. “The best thing he has going for him is his relationship with Hannity,” a conservative operative told New York magazine’s Olivia Nuzzi for a December profile of Oz. 

Hours after Oz announced his candidacy, Hannity gave him the opportunity to pitch himself to the Fox audience. Introducing Oz for that November 30 interview, Hannity stressed that Oz had “a lot of similarities” to Trump, and he highlighted their personal friendship and their “many conversations, too numerous to count, late into the night” at the start of the pandemic.

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.