Pennsylvania’s leading Republican candidates for Senate clashed over who has true conservative credentials and genuine ties to the commonwealth Wednesday morning, as front-runners Dave McCormick and Mehmet Oz appeared together on a public stage for the first time.

The two sparred at a forum in Erie after months of waging their campaigns by TV, hammering each other with millions of dollars in ads. They were joined by rivals Kathy Barnette and Jeff Bartos. And while the organizers had set up rules against personal attacks, the candidates quickly took opportunities to dig at Oz, the celebrity surgeon better known as “Dr. Oz.”

Pennsylvania’s Senate race is one of the most crucial in the country, with the outcome likely to help decide control of the chamber.

» READ MORE: Who's running for Pa.'s open Senate seat in 2022?

Here are some of the key points from one of the first major confrontations of the GOP primary:

Enmity for Oz

Oz and McCormick are both big-spending front-runners, and polls show McCormick now leading overall, but it was the TV star who seemed to draw genuine enmity from some of his opponents.

“You should all ask yourselves: Why is everyone attacking me?” Oz said at one point.

“Because he’s a liberal,” interjected Barnette, sitting directly to his right.

At times the attacks seemed to take Oz aback, as he urged the moderator from the Manufacturer & Business Association to step in, noting that the candidates had agreed not to criticize one another.

» READ MORE: Mehmet Oz knows TV. Now his GOP opponents are turning Pennsylvania’s airwaves against him.

But those rules didn’t hold for long. When all of the candidates talked up Pennsylvania’s energy industry and argued for unleashing it with fewer environmental regulations, McCormick pointed to Oz’s past comments and written columns raising concerns about health risks around fracking sites, including air and water contamination, breathing problems for people who live nearby, and other problems.

“That is a lie, and you know it’s a lie,” Oz shot back.

McCormick’s campaign pointed to news reports detailing Oz’s past statements, including medical advice columns bearing Oz’s name as coauthor. His campaign has said those columns reflected the view of Oz’s coauthor, not the candidate. Oz also pointed to his recent endorsement from Rick Perry, the former Texas governor and energy secretary under former President Donald Trump.

The Manufacturer & Business Association invited five GOP candidates who met its criteria, including polling and fund-raising thresholds. Carla Sands, the former ambassador to Denmark, declined to attend, and two other GOP candidates on the ballot, Philadelphia attorney George Bochetto and Montgomery County attorney Sean Gale, didn’t meet the criteria, according to organizers.

» READ MORE: David McCormick surges past Mehmet Oz and other takeaways from a new Pa. Senate race poll

Barnette, a conservative commentator who has run a grassroots campaign and aligned with some of the most far-right figures in the state, said she had no choice but to hit out at the leading candidates Wednesday, since the ultra-wealthy Oz and McCormick infrequently appear with rivals during the already brutal primary.

“This is not a talk show. This is reality,” she said. “And we need people who understand what the issues are, that don’t simply sit in a room, learn our talking points, and then come back and parrot them to us.”

Residency questions

McCormick, a former hedge fund CEO and Army veteran, largely escaped direct attacks, and worked to promote his Pennsylvania roots, explaining how he grew in the state, even though he has more recently spent years in Connecticut and only moved back in recent months as he launched his Senate campaign.

“The majority of my life’s been in Pennsylvania, I have a family farm, and I feel a deep commitment to what I see happening in our state, and what I see happening in our country,” McCormick said.

But if his GOP opponents didn’t strike him, Democrats saw a future opening when he embraced the Trump tax cuts of 2017. They’ve used those cuts as a potent weapon against the GOP in the past and see wealthy Republicans like McCormick as especially vulnerable to criticism over a set of breaks that flowed to people at the top of the income scale.

» READ MORE: The super PAC hammering Mehmet Oz as a RINO is getting money from longtime Democratic donors

And his Republican rivals pointed to his and Oz’s recent relocations to Pennsylvania ahead of the Senate race.

Bartos, a real estate developer from Montgomery County who ran for lieutenant governor in 2018, repeatedly promoted his work supporting conservative causes in Pennsylvania, not-so-subtly noting that he’s been doing it for years.

“When we look to our televisions and see people, as I’ve been calling them, ‘political tourists’ … they’ve come in and they’re spending tens of millions of dollars,” Bartos said, while arguing that he and Barnette have been travelling the state listening to voters. “For me, this campaign has always been, from day one and always will be, about a deep love and a commitment to our commonwealth.”

Oz, who lived in New Jersey for decades, says he moved to his in-laws’ home in Montgomery County in late 2020. That was weeks after it became clear the Senate seat would be open.

» READ MORE: Does Mehmet Oz live in Pennsylvania?

Similar on policy, distinct on background

Speaking to a largely business-oriented audience in a city that has long depended on manufacturing and industry, the candidates largely agreed on policy: They urged more natural gas extraction in Pennsylvania, pointing to Russia’s invasion of Ukraine as evidence of the risks of relying on on foreign oil. They called for making the Trump tax cuts permanent. (Bartos even offered a rare moment of public praise for the incumbent Republican Senator, Pat Toomey, who wrote much of that law and is not seeking reelection.)

The candidates argued against government spending and the $1,400 relief checks President Joe Biden sent last year, blaming both for inflation. McCormick, in a move unusual for a Republican, also called for better focusing defense spending, instead of increasing it, and said both parties bear some blame for the national deficit. To varying degrees they all criticized what they called “woke” culture on the left.

The contrasts, instead, came as each laid out their backgrounds to make the case they have the best background to carry out those goals.

Oz argued that he “burned the boats” in giving up his TV show to run for Senate and said his history of fighting the establishment media and government would make him the strongest advocate for the state.

“Imagine being so compelled, so worried about your country, that you would give it all up and not feel an inkling of remorse,” Oz said. “I’ll be able to represent you with a bold, loud voice.”

McCormick argued that he would be ready “on day one” given his experience as a combat veteran, business leader and former government official who served in high-ranking positions in the George W. Bush administration. “I don’t think we have time for people who need on-the-job training,” he said.

Bartos pointed to his deep ties to the state and his work during the pandemic to deliver loans to small businesses. “My campaign isn’t about me,” he said, joking about his own struggle to promote himself. “Everything I do is about this commonwealth.”

And Barnette, after initiating several of the scraps on stage, promised to bring a sharper edge to the GOP to fight what she said were Democrats “putting their foot on our throat.”

“Our country is on fire right now,” she said. “And the Republican Party has this crazy notion that we only pick the richest person in the room who’s willing to run for office. How has that served us? … You need a fighter.”