PITTSBURGH — President Donald Trump and Democratic contender Joe Biden made stops in Pennsylvania Wednesday, seeking to carve out their support in the crucial battleground state.

Highlighting the dueling economic messages that could play out in the general election, Trump argued that his rollback of environmental regulations has created jobs while the former vice president accused Trump of abandoning the voters who put him in the White House.

Trump, speaking in Pittsburgh at a shale energy industry conference, sought to take credit for job growth in the energy sector and warned about what would happen if Democrats were elected in 2020.

"These Democrat plans would obliterate millions of American jobs, devastating communities communities across Pennsylvania," Trump said. Speaking about his Democratic opponents, he warned "what they would do to you would be unthinkable."

He also didn't miss the opportunity to attack Democrats over their impeachment inquiry.

"I've had the Mueller witch hunt, the Russia witch hunt. I have witch hunts every week. I say, 'What's the witch hunt this week?'" Trump said. The Democrats "are a nasty group of people," he added.

It was Trump’s second time in the Pittsburgh area since August when he traveled to speak at a Shell plastic plant, and this will be his 14th time in Pennsylvania as president.

That is not by coincidence. Campaign aides have said that winning Pennsylvania, along with Michigan, Ohio and Wisconsin, will be the biggest priorities for 2020.

The speech, while an official White House event, had the feel of a campaign rally at times. While attendees waited for the event to start, the same soundtrack heard at Trump rallies played. Along with the energy industry executives in the front of the room, there was a group of enthusiastic Trump supporters in the back, many in Make America Great Again hats, who broke out into chants of U-S-A. At one point, the event was disrupted by a handful of protesters.

Hours earlier on the other side of the state, Biden played to his northeast Pennsylvania roots during a speech in his hometown of Scranton. Biden argued that Trump has “forgotten about the forgotten American” he pledged to help in 2016 making a general election argument with the presidential primary in mind.

In what his campaign billed as a major economic address, the former vice president repeatedly reminded voters here of his middle-class upbringing and likened his family’s economic struggles to other Americans.

Biden said the lessons about the importance of dignity, integrity and community he learned growing up here were foreign to the president, saying Trump “doesn’t seem to have any sense of empathy for people.”

“I'm not sure Donald Trump has any idea what I'm talking about when I talk about the longest walk,” Biden said, referring to his father’s difficult path in telling the family they needed to move so he could find a job in Delaware. “You know, I think that the longest walk his father ever made was to drop off $400 million in his trust account.”

Trump may boast about positive economic statistics, but Biden said, to nods of agreement in the audience, that many working-class Americans continue to struggle while only the wealthiest Americans have benefited from Trump’s economic policies.

“Go back to your old neighborhoods. Ask them how they are doing. How they are feeling. They are in trouble,” he said. “You were all raised to believe that if you worked better, you worked hard, you could even be better off than your parents. But not today.”

Biden didn’t unveil new policy proposals Wednesday, but ticked through several already announced that he said would help “rebuild the backbone of America,” the middle class. They include raising the minimum wage, building on the Affordable Care Act with a public option, and providing free community college. But he largely kept his focus on the president.

“We don't deserve a president who goes out of his way to make life in America harder, crueler, pettier. He said he's working for the forgotten American. But we've forgotten about the forgotten American,” Biden said. “The American middle class brings dignity and integrity every day to work. They deserve the dignity and integrity reflected in their leaders.”

While Sen. Elizabeth Warren, D-Mass., has surged to join Biden as a front-runner in a shrinking primary field, Biden has been increasingly willing to spar with his fellow Democrats after months of trying to coast above the fray. Just last week, after the fourth debate, he slammed Warren for failing to be “candid and honest with the American people” about the cost of her signature plans, especially health care.

Part of his appearance Wednesday in Scranton was to send a more subtle message about what his campaign feels is Warren’s inability to carry areas of the country like this one which Trump turned from blue to red. Hillary Clinton narrowly carried Lackawana County, while neighboring Luzerne County saw one of the largest flips from the 2012 election, when the Obama-Biden ticket narrowly carried it, to 2016, when Trump won by nearly 20 points.

Biden surrogates maintain that he is unique among the top Democratic contenders in being able to win over swing voters in swing states, even as many public polls at this point also show other Democrats leading Trump in key battlegrounds.

Biden also targeted Trump on Syria, saying his making foreign policy decisions on a “whim” was damaging America’s credibility.

“Who's going to believe America's word as we give it?” he asked. “That's what a president does. He speaks for Americans. He keeps commitments. … What are our allies sitting there thinking?”