Pennsylvania. It was the center of the political universe. If you were watching the returns on that Tuesday night in November, things looked one way—red, very red. But by Saturday morning, the world had turned upside down. People still argue about what happened, but the data tells a very specific, numbers-driven story of a state that basically underwent a massive demographic and geographic tug-of-war.
Joe Biden won. He took the state’s 20 electoral votes by a margin of about 80,555 votes. That’s roughly 1.2% of the total ballots cast. To put that in perspective, it’s about enough people to fill the Eagles’ stadium. Not exactly a landslide, right? But in a state that Donald Trump won by a mere 44,000 votes in 2016, it was the shift that decided the presidency.
Understanding how did PA vote in 2020 requires looking past the big blue and red map. You have to look at the suburbs, the "T" (that massive rural stretch in the middle), and the mail-in ballot boxes that sat in the middle of a once-in-a-century pandemic.
The Massive Urban-Suburban Surge
Philadelphia is always the powerhouse for Democrats. That’s no secret. Biden walked away with over 600,000 votes there. But here’s the kicker: he actually did slightly worse in the city itself compared to Hillary Clinton in some neighborhoods. The real story isn't the city. It's the "collar counties."
Montgomery, Delaware, Chester, and Bucks. These four counties surrounding Philly were the engine room of the Biden victory. These areas are filled with college-educated voters who used to be "Rockefeller Republicans" or independents. In 2020, they swung hard. In Montgomery County alone, Biden racked up a lead of over 131,000 votes. That single county essentially wiped out dozens of smaller red counties combined.
It’s about the margins.
Trump actually increased his raw vote totals in many rural areas. He was incredibly popular in places like Luzerne County—a former Democratic stronghold that has shifted right. But he couldn't outrun the math in the suburbs. The "Blue Wall" didn't just reform; it got reinforced with suburban stucco.
The Mail-In Ballot Explosion
We have to talk about Act 77. This was the state law passed in 2019—ironically with bipartisan support—that allowed no-excuse mail-in voting. Then COVID-19 hit. Suddenly, voting by mail wasn't just a convenience; for millions, it felt like a necessity.
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Over 2.6 million Pennsylvanians voted by mail.
Because of state law at the time, officials couldn't start processing those envelopes until 7:00 AM on Election Day. This created the "Red Mirage." On Tuesday night, Trump held a massive lead because the in-person votes (which leaned heavily Republican) were counted first. As the week went on and the mail-in ballots (which leaned roughly 3-to-1 Democratic) were scanned, that lead evaporated.
It wasn't magic. It was just math. It was the physical reality of opening millions of envelopes by hand.
Why the "T" Wasn't Enough
If you look at a map of Pennsylvania by land area, it’s a sea of red. The "T"—the central and northern rural counties—voted for Trump by staggering margins, sometimes 70% or 80%.
- Potter County: Trump +60
- Bedford County: Trump +67
- Tioga County: Trump +50
But cows don't vote. People do.
While Trump was maximizing his base in the rural interior, the population in those areas is stagnant or shrinking. Meanwhile, the Lehigh Valley—places like Allentown (Lehigh County) and Easton (Northampton County)—was booming. These are "bellwether" counties. Historically, whoever wins Northampton wins the state. In 2016, Trump took it. In 2020, Biden flipped it back by less than 1,000 votes.
The Erie Flip
Erie County is the quintessential swing region. It’s blue-collar, industrial, and has a lot of "Obama-Trump" voters. In 2016, Trump became the first Republican to win Erie since the 80s. It was a sign that the Democratic grip on the working class was slipping.
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In 2020, Biden reclaimed Erie.
He didn't win it by much—only about 1,400 votes—but it signaled that the Democratic message on labor and "Scranton Joe" branding had just enough resonance to stop the bleeding in the Rust Belt. It’s a game of inches. If Trump holds Erie and trims the lead in Bucks, we’re looking at a completely different historical timeline.
Breaking Down the Demographics
Honestly, the exit polls gave us some weird insights that people still debate. Biden did better with white men than Clinton did, which helped him in the suburbs. Trump, surprisingly, made slight inroads with Latino voters in places like Reading and Hazleton, though not enough to flip the counties.
The youth vote was also huge. Turnout among voters under 30 in PA was significantly higher than in 2016. Most of these voters weren't necessarily "in love" with Biden, but they were highly motivated to vote "against" the incumbent.
It was a high-stakes, high-emotion environment. Total turnout was nearly 71%. That’s astronomical for Pennsylvania. People weren't just "kinda" interested; they were obsessed.
The Legal Battles and Audits
You can't discuss how did PA vote in 2020 without mentioning the aftermath. The weeks following the election were a blur of court challenges. There were suits about the deadline for mail-in ballots, suits about observer access in Philadelphia, and claims about "curing" ballots (fixing mistakes on the envelope).
None of these challenges changed the outcome.
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The Pennsylvania Supreme Court and various federal courts—including judges appointed by Trump—consistently found that while there were minor administrative hiccups, there was no evidence of widespread fraud that could have overturned an 80,000-vote margin.
Post-election audits, including a "risk-limiting audit" conducted by the Pennsylvania Department of State, confirmed the accuracy of the machines. Basically, the paper trail matched the digital tallies.
The Actionable Takeaway: What This Means for Future Elections
If you're looking at Pennsylvania as a strategist or just a curious citizen, the 2020 data offers a clear roadmap. The state is no longer a "Rust Belt" monolith. It’s a fractured landscape.
To win Pennsylvania now, you have to follow a specific "menu":
- Run up the score in the suburbs. The Philly collar is the new kingmaker.
- Minimize the "T" losses. A Democrat doesn't need to win rural PA; they just need to lose it 60-40 instead of 80-20.
- Hold the Bellwethers. Keep a close eye on Erie and Northampton. They are the early warning system for the entire state.
- Master the Mail. Mail-in voting is here to stay. Campaigns that don't have a robust "chase" program for mail-in ballots start the game at a massive disadvantage.
The 2020 election wasn't a fluke. It was the culmination of a decade-long shift in where people live and how they identify culturally. Pennsylvania remains the ultimate "purple" state because it contains both the deep-red future of the GOP and the high-density blue future of the Democrats, all trapped inside the same borders.
Check the official Pennsylvania Department of State election returns for the raw, precinct-level data if you want to see exactly how your own neighborhood moved the needle. Knowing the numbers is the only way to cut through the noise of the political commentary that usually surrounds this topic.