It’s tempting to think that Pennsylvania’s political map is settled in this presidential election year. And it’s true that the state’s northeastern and southwestern coal regions, once Democratic, are set to reward Donald Trump again. Philadelphia’s “collar” counties, meantime, will continue their Republican purge. But the outcome of this battle of the voting margins—working class versus suburbanite—still remains unpredictable. 

The Lehigh Valley, the most populous region between Philadelphia and Pittsburgh, will prove the bellwether in this fight. Its cities and towns have already had an understated yet immeasurable impact on America’s economy and history. Come November, its voters could determine Trump’s fate in Pennsylvania—and his reelection. 

Centered in Lehigh, Northampton, and southern Carbon counties, the Lehigh Valley lies between the endless Blue Mountain range—gateway to the Poconos—and the lower South Mountain range. Driving eastward on the truck-congested Interstate 78 or Route 22, past the distribution centers and chain hotels, Allentown sprawls across the landscape, its low-density scale betraying its distinction as Pennsylvania’s third largest city. Downtown, the art deco PPL Building—reminiscent of the Rockefeller Center—stands as the valley’s tallest structure, overlooking row homes that transition to retail strips, small boroughs, and then the bucolic farmland that once made this region the breadbasket of colonial America.  

The Lehigh Valley has experienced a demographic transformation since that time, when Pennsylvania Dutch farmers sold wheat and rye on credit to the Continental Army. From the 19th century onward, a diverse geology—iron, limestone, zinc, and slate—turned the Lehigh Valley into an industrial and transportation behemoth that swelled its population. Today, the region continues to grow even as Pennsylvania’s population stagnates. 

This unremitting demographic change makes the Lehigh Valley a perpetual toss-up in presidential elections. But its shifting voting patterns—driven in part by blue-collar families, affluent transplants, and Latino neighborhoods—often predict statewide outcomes. Northampton County, for example, has voted for the winning presidential candidate in nearly every election since 1932. “Northampton is a great microcosm of the state, and to a slightly lesser degree, the country,” said Christopher Borick, director of the Muhlenberg College Institute of Public Opinion. “I think Northampton is the bellwether county.”

In 2016, Trump enjoyed a surprisingly strong performance in the Lehigh Valley. Northampton County, despite a Democratic advantage among registered voters, supported the GOP nominee for the first time since 1988. Though Clinton won Lehigh County, home to Allentown, her winning margin was comparatively smaller than Barack Obama’s in 2008 and 2012—another factor in Trump’s winning the state by just 44,000 votes. It was Northampton’s preference for Trump, however, that played a crucial role. Northampton was just one of three counties—joined by Luzerne and Erie—that went for Obama twice before flocking to Trump. Yet it didn’t easily fit Trump’s message of American carnage. “It isn’t as perfectly molded to the Trump model as a place like Luzerne or Erie because its economic status is better,” said Borick. “And so, it’s not the safest place for Trump to retain the results of 2016.”

Since the Great Recession, Northampton County has reaped the benefits of the Lehigh Valley’s economic transformation, marked by its greatest period of growth since the early 20th century. It’s now among the nation’s fastest growing regions, with a $41.2 billion GDP—more than Vermont and Wyoming. Due to its advantageous location, not far from metro New York, the Lehigh Valley is also among the nation’s largest logistics hubs, ranking second globally for growth in industrial rents. Its highway network is packed with trucks at all hours, which serve 40 percent of U.S. consumers along the eastern seaboard. These trucks drive to and from multi-million square foot distribution centers—such as FedEx, Walmart, Amazon, and QVC—sprouting off highway exits and employing thousands. 

The Lehigh Valley is also home to top universities, massive health care systems, advanced manufacturing, and Fortune 500 companies, including chemicals giant Air Products, which is building a $400 million new global headquarters. In addition, the region’s cities—Allentown, Bethlehem, and Easton—are enjoying an urban renaissance. Since 2010, Allentown, long associated with decline, has undergone about $1 billion in new and planned downtown development, thanks to a state-created special taxing district. Center City Allentown, once blighted and empty, now features a sports arena, restaurants, apartment buildings, high rises, and a new office for ADP, the global payroll company, that employs over 1,000 associates. 

The region defies every Rust Belt trend, as well as its own recent past. After all, a quarter century ago, the Lehigh Valley seemed ready for an obituary. Billy Joel even wrote a hit song about it. In 1995, Bethlehem Steel, the nation’s second largest steelmaker, closed after 130 years of operation. Seventy years earlier, its chief engineer had declared that “Bethlehem Steel owned New York.” For decades, its steel helped build the nation’s landmark skyscrapers and bridges, from the Empire State Building to the Golden Gate Bridge. Over time, cheaper foreign steel, particularly from China, extinguished an industry that once contributed, directly and indirectly, to the wages of 40 percent of Americans. 

The Lehigh Valley became a region that thought in the past tense. At one time, its steel, slate, and cement industries shaped industrial America, while its rivers and railroads transported anthracite coal that fueled big cities. Through the late 20th century, however, it was beset by industrial decline. By 2008, even Mack Trucks, once synonymous with Allentown, had moved its headquarters to North Carolina. When Bethlehem Steel closed, one furnace operator advised evacuation. “There’s nothing here for them anymore,” he told the New York Times. “Just a town looking over a graveyard.” Today, that graveyard is home to SteelStacks, an arts and events venue that’s also the nation’s largest revitalized brownfield. 

Though prosperous days are here again, regional discontent has intensified with economic and demographic change. In particular, industrial and suburban sprawl imperils the Lehigh Valley’s formerly agricultural character, now accounting for less than a quarter of the region’s 726 square miles. Massive distribution centers, the size of several football fields, are built seemingly overnight on farmland. The structures house new employers, but their presence—compounded by increasing traffic—divides the region. The working class, for example, questions the quality of jobs. “There’s a lot of job opportunities,” one maintenance worker recently told the Times, “but it’s harder to make a good wage.” Newer residents, meantime, express dismay over the proliferation of warehouses near suburban developments. In response, several townships have approved income tax increases to preserve open space.  

These newer residents ensure the Lehigh Valley’s toss-up status in presidential races. Northampton County’s cultural foundation remains traditionally working-class, but scores of younger professionals continue to relocate—or stay—for the region’s employment opportunities, affordable housing, and excellent schools. The Lehigh Valley has become a refuge for people fleeing metro New York’s unsustainable costs. But these transplants are hardly loyal to Republicans, as reflected in post-Trump election cycles. In 2018, Democrat Susan Wild won the Lehigh Valley-based congressional district, succeeding Republican Charlie Dent, who retired. And in 2019, Democrats took control of Lehigh County’s board of commissioners for the first time in 40 years. Trump prevailed in 2016, but subsequent local voting patterns are more reflective of suburban Philadelphia than western Pennsylvania. 

In 2016, Trump’s message of economic decline resonated with the Lehigh Valley’s working- and middle-class voters. Ironically, the region could deny him an encore performance this year despite its resounding comeback. The election will prove a cultural clash, pitting the conservative blue-collar worker—with regional roots dating back generations—against the liberal well-to-do suburbanite who just relocated from New York. As part of Philadelphia’s media market, the region will require big campaign dollars from Trump and the Democratic candidate to reach its voters. And if Trump holds a rally in Allentown’s downtown arena, he’d better keep Joel’s song off the playlist. The region never looked better, and if enough of its newer residents stand in line, he could lose Pennsylvania’s invaluable electoral votes—and the election. 

Charles F. McElwee is assistant editor of City Journal. Follow him on Twitter @CFMcElwee.