With 20 Electoral College votes at stake here, Trump could win nearly every other "toss-up" state -- including important battlegrounds like Florida, Ohio and North Carolina -- and still lose the election if he doesn't carry Pennsylvania.
And because Democratic nominee Hillary Clinton appears to have the state's densely populated urban areas like Pittsburgh and Philadelphia locked in her favor, Trump needs Pennsylvania's rural areas and smaller, working-class cities like Scranton to come out on top.
The problem? Republicans are outnumbered by registered Democrats by almost a million votes.
"The joke around here is that if you vote Republican on Tuesday, you've got to go to confession on Saturday," said Vince Galko, a veteran Republican strategist in Pennsylvania who has worked on former President George W. Bush's re-election effort here. "Voters in this part of the state have been trained over the years to pull that straight Democratic lever, so it's a challenge for Republicans to get people to split their ticket."
The registration gap, however, has shrunk this election season. About 100,000 Democrats have switched their party identification to Republican, according the Pennsylvania Department of State, outnumbering the nearly 40,000 Republicans who became Democrats.
Trump's campaign has made a concerted effort to make inroads among working-class Democrats here, a voting group he'll need to win the state.
Trump's "America First" message is resonating with longtime Democrats like Debbie Merrigan, a server at the Bucktown Diner in nearby Dunmore who switched her party identification during the last election cycle.
Merrigan said she believes immigrants are receiving special treatment from the government at the expense of natural-born Americans, and worries about the influx of refugees fleeing war-torn Syria.
"I've always been Democrat. I switched," said Merrigan. "I'm all for Trump. You've got people coming over. ISIS. It's scary, and you don't know when it's going to happen. With Trump, he can actually do something to stop it and hopefully build a better life for us Americans."
Trump and his vice presidential nominee, Indiana Gov. Mike Pence, have made several trips to the area, but it might not be enough to tip the scales here. Polls have consistently shown Clinton leading in the state, and a Bloomberg Poll taken in October found Clinton leading in Philadelphia's four suburban counties by 28 percentage points.
"The real issue is intensity versus registration. Can Donald Trump's intensity overtake the Democrats registration?" said Galko. "He can't match the Democrats registration, but he's hoping Democrats can't match his intensity."