Pennsylvania was a pivotal state in the 2020 presidential election, sealing Joe Biden’s victory over Donald Trump after four days of vote counting. So it’s no surprise the Keystone State is again front and center this election cycle, with both Vice President Kamala Harris and former President Donald Trump investing time and resources there ahead of Election Day.

In the past few weeks, the presidential candidates have been regulars in Pennsylvania, often joined on the campaign trail by celebrities and fellow politicians. They’ve made some memorable pit stops — from Harris snapping selfies at Famous 4th Street Deli to Trump donning an apron during a campaign event at a McDonald’s in Bucks County, which Pennsylvania Gov. Josh Shapiro calls the “swingiest of all swing counties in the swingiest of all swing states.” Trump also returned to Butler for a rally at the same fairgrounds where he survived an assassination attempt in July.

CBS News’ Battleground Tracker shows an effectively tied race in Pennsylvania a week before Election Day. The state is part of the Democrats’ “blue wall” along with Michigan and Wisconsin, considered crucial for the party’s path to the White House. 

Here’s what you need to know ahead of Election Day:

Pennsylvania Election Day fast facts

• Polls open: 7 a.m. ET
• Polls close: 8 p.m. ET
• Mail-in ballot deadline: 8 p.m. ET on Tuesday, Nov. 5, 2024
• Where to vote: Look up your polling place here
• Electoral votes: 19
• Voter turnout: 76% of registered voters cast ballots in 2020, government data shows

Pennsylvania vote-counting rules

Every state has its own rules when it comes to vote counting. In Pennsylvania, state law requires county election workers to wait until polls open on Election Day (7 a.m. ET) to start processing — removing ballots from envelopes — and counting mail-in ballots. 

Pennsylvania counties also can’t begin to record or release mail-in ballot results until after the polls close at 8 p.m. ET. That means there will be a lag in announcing the final tallies and, in turn, projecting the state’s winner. How long of a delay, however, is unclear.

Pennsylvania’s Electoral College votes

Pennsylvania has 19 electoral votes, making it an important prize in the presidential race. The state had 20 electoral votes in the 2020 race but lost one in the congressional redistricting that followed the 2020 Census.

When will we know who won Pennsylvania?

In 2020, Mr. Biden was named the projected winner of Pennsylvania late morning on Saturday, Nov. 7 — the fourth day of vote counting — after taking an insurmountable lead in the state. Winning the state’s then-20 electoral votes helped him top the 270 needed to win the presidency.

But it’s hard to draw any conclusions from 2020 when more voters opted for mail-in voting for the first time due to the ongoing spread of COVID-19. It was the first year Pennsylvania allowed no-excuse mail-in voting, leading to a record 2.6 million mail-in ballots. In 2020, 38% of Pennsylvanians voted either early or by mail, compared to 4% in 2016, according to CBS News’ records.

The Pennsylvania Supreme Court also ruled in 2020 that mail-in ballots couldn’t be rejected over signature mismatches.

Kathy Boockvar, former Secretary of the Commonwealth of Pennsylvania, told CBS News that 2024 will likely look different since election officials have had four more years of practice, bought new equipment and have a better idea of how much staffing they’ll need.

“Nobody knows on election night who wins or loses. What we hope to do is count the ballots securely, accurately, and then after that as quickly as humanly possible,” Boockvar said.

In 2020, about 54% of total votes cast were reported by 12 a.m. ET after Election Day, according to the Associated Press. The “overwhelming majority of ballots” were counted by Thursday night into Friday morning in 2020, according to Boockvar.

Boockvar estimates this year, given all of the lessons learned from 2020 and improvements made to the counting system, that the majority of ballots will be counted by the end of Wednesday instead of Thursday, which may help speed up the process of projecting a winner.

However, if the race is close, then that may delay things further. Pennsylvania has an automatic recount if the margin in any statewide race is 0.5% votes or less. The state also allows losing candidates to file a request for a machine recount if they pay for it. A refund may be available depending on the findings. 

Could Latino voters in Pennsylvania decide the election?

In order to secure a Pennsylvania victory, both Harris and Trump may need to win over Latino voters. There are nearly 580,000 eligible Latino voters in Pennsylvania, according to the UCLA Latino Policy & Politics Institute’s latest data. Pennsylvania’s share of eligible Latino voters has more than doubled since 2000, the data shows.

Roughly about half of the Latino population lives in the center part of the state called the “222 Corridor” — a stretch of small cities including Reading, Allentown, Lancaster and Bethlehem, where the presidential candidates and their running mates have visited frequently.

A recent poll from the Hispanic Federation and Latino Victory Foundation found that 66% of Latino respondents said they’d vote this year in Pennsylvania.

Who won Pennsylvania in past presidential elections?

Pennsylvania has voted for the presidential winner dating back to 2008, when Barack Obama was elected president. Here’s a look at who has claimed the state over the years:

• 2020: Democrat Joe Biden defeats Donald Trump
• 2016: Republican Donald Trump defeats Hillary Clinton
• 2012: Democrat Barack Obama defeats Mitt Romney
• 2008: Democrat Barack Obama defeats John McCain
• 2004: Democrat John Kerry defeats George W. Bush
• 2000: Democrat Al Gore defeats George W. Bush