In their first debate, U.S. Sen. Bob Casey embraced a message of bipartisanship, while the man seeking to unseat him in November, U.S. Rep. Lou Barletta, embraced President Trump.

"This president understands how to get the economy going," the Republican from Hazleton said Saturday afternoon.

Throughout the hour-long debate at 6ABC's station off City Avenue, Barletta raised the economy's strength as an argument for his candidacy.

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Casey, meanwhile, argued that Republican tax cuts exploded the deficit and created few benefits for the middle class.

"It has not done anything to lift wages in America and that's what should have happened," the two-term senator said. "We should have passed a tax bill that said we're going to give the middle class a huge, substantial, tax cut."

Polling website Real Clear Politics showed that Barletta is trailing Casey by double digits in the race for the Senate seat, and the congressman was the more aggressive of the two, and more frequently attacked Casey and Democrats.

"They don't know how to get the economy going; they can't," he said of Democrats. "They don't understand it."

Casey, a low-key speaker, was by contrast staid in his responses. He emphasized his willingness to reach across the aisle and find common ground with Republicans on policy, including immigration, education, and health care.

"At long last, we should come together in a bipartisan way, as one American family, and fix this broken system," Casey said of immigration.

He seemed to bristle, though, when Barletta said Casey was opposed to an energy-friendly policy in Pennsylvania, referring to the state's natural gas resources.

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"For the record, I don't oppose energy," Casey said. "That's a dramatic statement."

Barletta, who came to prominence after passing a law while mayor of Hazleton to bar renting residences to or employing illegal immigrants, used a mention of a caravan of Honduran migrants approaching the Mexican border with Guatemala to emphasize the need to secure the nation's borders.

"If you think this caravan now is a problem, let them get in charge again," Barletta said of Democrats. "You'll see people rushing the border."

Casey strongly opposed family separation at the border, he said, and supported legislation that would provide border security, while creating a path to citizenship and a way for jobs often held by undocumented immigrants to be filled.

The two expressed differences on health care, with Casey supporting the protections of the Affordable Care Act, the opportunity of people 55 and older to buy into Medicare, and a focus on reducing health-care costs.

Barletta voted to repeal the Affordable Care Act, saying it is a disaster, but said he would have only supported a replacement that protected people with preexisting conditions.

The debate, moderated by 6ABC anchor Jim Gardner, touched on most major national issues. Gardner pressured the candidates when they didn't directly answer questions, particularly focusing on Barletta's stumbling response to whether Special Counsel Robert Mueller, who is investigating Russian interference in the 2016 election, should be protected by legislation from firing. Barletta initially said he supported protections before finally saying, "I wouldn't vote for that."

Barletta, asked about a recent United Nations report that found the world had as little as 12 years to prevent environmental catastrophe due to climate change, dodged a question about whether he believed climate change was man-made.

Casey didn't hesitate to say climate change was man-made, but hedged on two policies supported by the party's progressive wing. He said of a single-payer health-insurance system and supervised injection sites for people facing opioid addiction, that he would need to "know a lot more about it." Barletta opposed both ideas.

Just before the debate, an advertisement run by Casey focused on a mother expressing concern that her child with cancer might not have health care if Barletta is elected. The spots sparked a furious reply from Barletta, whose own grandson is being treated for cancer.

Casey, in his closing statement, apologized for the advertisements, but Barletta still wanted a more personal mea culpa to his family.

“We don’t know if Jordan is going to be OK,” Barletta said of his grandson after the debate.