In the 1950s, Scranton, Pa., was at the start of a long, slow decline. The coal mines that had fueled the city’s early prosperity were shutting down, leaving residents to cope with gaping sinkholes and a scarred landscape. Textile factories, too, were on their way out, and thousands of people picked up and left for better opportunities elsewhere. Joining the exodus were 10-year-old Joe Biden and his family. Unable to find a steady source of work, Biden’s father, Joe Sr., had been commuting to Wilmington, Del., to clean boilers. By 1953, he decided it was time to move the whole family across the state lines.

Biden, who was in grade school at the time, presumably didn’t have much say in the matter. But that didn’t stop President Trump from declaring on Monday night that the Democratic presidential contender had abandoned Pennsylvania.

“Biden deserted you,” he told the crowd at a campaign rally in Montoursville, Pa., located about 80 miles west of Scranton. “I guess he was born here, but he left you, folks. He left you for another state.”

The eyebrow-raising assertion received only a muted response from the audience, suggesting that even Trump’s die-hard supporters weren’t necessarily sold on the claim. Over the years, Biden has repeatedly referenced his Scranton roots, which pundits see as a strategic political move geared to appeal to working-class voters in a crucial swing state. But locals have consistently insisted that his affection for the hardscrabble city is genuine.

You think it’s an opportunist thing, but it’s not,” his childhood friend, Tom Bell, told the Scranton Times-Tribune in 2008. “The guy’s that way. He’s always been. Before he was even in the limelight.”

The former vice president’s ties to the area go back generations. Biden, a noted genealogy enthusiast, took part in a question-and-answer session for Ancestry.com in 2016 where he described how his great-great-grandfather had moved to northeastern Pennsylvania in 1851 after emigrating from Ireland. Scranton was where his grandparents, and his parents, had met, he said. After moving away in the fourth grade, he continued to spend most of his summers and holidays there, visiting his mother’s family in the same middle-class, predominantly Irish Catholic neighborhood where he had spent his early years.

“My mother would go on to live in Delaware more than 50 years, but when you asked Jean Finnegan where she was from, she’d say ‘Scranton,’” he added.

Though Biden went on to have a decades-long political career in Delaware, where he was first elected to the Senate at the age of 29, he maintained close ties to his home state. During his time in office, he became known as “Pennsylvania’s third senator” due to both his Scranton roots and the fact that large swaths of Delaware could be considered a suburb of Philadelphia.

“For the last thirty-five years, any time Scranton needs something … I don’t know how to say no to them,” Biden told GQ in 2010. “For real. I really don’t. You know, it’s still home.” Almost half of the groomsmen who took part in his wedding to his first wife, he pointed out, were from the city.

When Barack Obama chose Biden as his running mate in 2008, those Pennsylvania connections were seen as a valuable asset that could help the campaign appeal to socially conservative, blue-collar voters throughout the state, which had emerged as a key battleground. “While Biden brings experience and foreign policy cachet to Obama’s national campaign, he brings to Pennsylvania an affection for the state that voters may reward,” noted the Morning Call of Allentown, Pa.

Biden didn’t hesitate to play up his middle-class Scranton roots during the 2008 campaign, frequently referencing the city in stump speeches and taking reporters to visit his boyhood home, where he would reminisce about his aunt’s rice pudding. Friends confirmed his account of an idyllic, all-American childhood that featured Little League games and wholesome pranks, and one local newspaper reporter noted approvingly that Biden “can name city streets, churches, old-time politicians and businesses that operated here.”

He wasn’t the only candidate in that year’s election cycle to highlight his ties to the city. While competing in the Democratic primaries, Hillary Clinton heavily emphasized her personal connection to Scranton, where her grandfather worked in a lace mill. Though Obama ultimately clinched the nomination, Clinton won Pennsylvania’s Democratic primary. The Obama campaign may have taken note: At the Democratic National Convention that year, Obama introduced his vice-presidential pick as “a scrappy kid from Scranton who beat the odds.”

Biden’s acceptance speech, too, made frequent reference to his upbringing in the city. Afterward, one CNN commentator joked, “I think they mentioned Scranton more than they do on ‘The Office.’”

Challenged with a declining population and near-stagnant economic growth, Scranton suddenly found itself at the center of the political universe. Meredith Vieira, on NBC’s “Today” show, declared it “the symbolic ground zero of this general election season.” Another journalist concluded that it was the new Peoria, Ill. — “ground zero for old-fashioned American values, the psychic heartland.”

It was also still Biden’s hometown, even if he hadn’t lived there for decades.

“On election night, I wanted to know the results of one place,” he later told GQ. “I wanted to know what the results were in northeast Pennsylvania.”

Voters in Lackawanna County, where Scranton is the largest city, came through. Obama won the state with 63 percent of the vote in 2008, performing better there than in any other part of the state besides Philadelphia. The same pattern was repeated again in 2012, when Obama faced off against Mitt Romney and again handily won Lackawanna while receiving 63 percent of the vote in Pennsylvania.

“It’s a loyal area, man,” Biden told GQ. “There used to be an old bad joke. I hope it’s not so much a good joke anymore. ‘Everybody’s from Scranton, no one’s in Scranton.’”

The same joke could easily apply to Biden, who has spent most of his life away from the city but never seems to miss an opportunity to mention his Scranton upbringing. As anticipation around his prospective presidential bid heightened in April of this year, he was spotted wandering the city’s streets with a camera crew. Political junkies immediately deduced that he was filming a campaign ad. Sure enough, within weeks, Biden had announced his candidacy. His first campaign speech, which took place in Pittsburgh, naturally featured a shout-out to Scranton. Like his adopted hometowns of Wilmington and Claymont, Del., he said, the city was “made up of hard-working, middle-class Americans who are the backbone of this nation.”

Biden’s rise to the highest echelons of American politics appears to have inspired a certain amount of hometown pride among Scranton residents, who had previously grown accustomed to seeing their city used as a punchline in “The Office.” But not all of them are convinced that he should be the next president. Elaine Donly, a 64-year-old Scranton resident, told the Philadelphia Inquirer in January that Scrantonians see Biden as “one of us.” Still, she said, there was a need for “young, fresh blood” in the White House, and she wasn’t sure Biden was the right person to unite the country.

Being from the city made it even harder to decide whom to support, she added: “We have a hometown boy. We want to throw him up on our shoulder like the quarterback after a winning game.”

Any candidate hoping for victory in 2020 will first have to win over voters in Pennsylvania, which carries 20 votes in the electoral college and is seen as a key swing state that could potentially be picked up by Democrats. At his rally on Monday, Trump, who won the state by less than one percentage point in 2016, made a direct appeal to voters, arguing that he has done more for the region’s economic prosperity than the former vice president. (In Lackawanna County, where Biden campaigned for Hillary Clinton in 2016, the Democrat won just slightly over 50 percent of the vote.)

“This guy talks about ‘I know Scranton,’" the president said of Biden. “Well, I know the places better. He left you for another state and he didn’t take care of you, because he didn’t take care of your jobs.”

One 18-year-old in the audience evidently agreed, telling HuffPost that Biden was “only from Pennsylvania when he wants votes.”

“You can’t be from two states at once,” he said.

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