Get to know the U.S. voters who matter most in the 2024 presidential election

Bill Donovan knows that every vote counts in the swing state of Pennsylvania.

That's why the 78-year-old Democrat traveled from university to university across Pittsburgh, reaching out to students in cafes and on sidewalks to ensure they registered to vote.

Mr. Donovan plans to support Vice President Kamala Harris in the 2024 presidential election and volunteer with a nonprofit voter registration group aimed at increasing Democratic turnout in the state.

With 19 electoral votes – the most electoral votes of any swing state – Pennsylvania has become the must-have prize in this election, putting everyday voters in the spotlight.

Mr. Donovan said they had to take advantage of that.

“A lot of people are saying that this is where the decision will be made… and I think they might be right,” he told the BBC. “It gives us a little more motivation to keep going when we feel like going home.”

How Pennsylvania votes is often seen as a predictor of who will win the country – the candidate who won the state in 10 of the last 12 presidential elections ended up in the White House.

The state has a history of close races. Former President Donald Trump won Pennsylvania in 2016. Four years later, President Joe Biden narrowly won. And just days before Election Day, polls show there's a dead heat between Harris and Trump.

The power that comes with voting in Pennsylvania is exactly why Dimitri Chernozhukov, a 21-year-old student at Lafayette College in the town of Easton, chose to attend college in the state.

“My vote counts here,” said the future two-time Trump voter. “When I registered in Pennsylvania, I made sure all the forms were correct because this vote is important.”

The state has been flooded with campaign stops by Harris and Trump, who along with their running mates have made a total of more than 50 appearances in the state since mid-July.

Kari Holmes, a pastor in eastern Pennsylvania, sees the spotlight on her state and feels the burden of being one of its coveted constituents. She has worked with other faith leaders to encourage voters of color, a high-demand demographic, to vote.

“This is the time to feel the importance of our voice as voters of color in this very important commonwealth,” said Ms. Holmes, who plans to vote for Harris.

With approximately nine million registered voters in Pennsylvania, voter turnout is critical to the success of both campaigns in November.

Registration numbers show that political affiliation is nearly split in half: about 3.9 million registered Democrats and 3.6 million registered Republicans. In addition, there are about 1.4 million independent or third-party registered voters who have been courted by both campaigns.

Marc Pane, owner of an auto repair business in the city of Scranton, is among the millions of registered Republicans looking forward to voting for Trump in November.

“It could come down to Pennsylvania,” Mr. Pane said. “We could win or fail the election. It is important. Our voice is more important than ever and I’m really glad we are.”

In Pennsylvania, Democrats are mostly gathered on the eastern and western borders in urban areas like Pittsburgh and Philadelphia. The rural center of the state is heavily Republican.

Two counties in particular — Erie in western Pennsylvania and Northampton in eastern Pennsylvania — are considered leading counties, meaning they often trend toward how the entire country votes. Both counties favored Trump in 2016 but went for Biden in 2020.

“You have the balance of urban, rural and suburban and it's really a place to go on election night to see what's happening,” Christopher Borick, director of the Muhlenberg College Institute of Public Opinion in Pennsylvania, told the BBC.

Lori McFarland, chair of the Lehigh County Democrats, spends her days making sure Pennsylvanians in Lehigh County, which borders Northampton County, support Harris. She's not sure every voter understands the gravity of their decision on Nov. 5.

“It’s a challenge to not get too excited, stay calm, stay focused and know what the job is,” Ms. McFarland said. “There is pressure because both the campaigns (and) the world is looking not only at Lehigh and Northampton counties, but also at Erie County.”

“We are the big three counties that feel like it's coming upon us, it's overwhelming,” she told the BBC.

The focus on voter canvassing in the crucial swing state is leading to an influx of political advertising.

According to a recent AdImpact report, the Harris campaign spent $159.1 million (£122.6 million) on advertising in Pennsylvania between July 22 and October 8. The Trump campaign spent $120.2m (£92.4m) in the same period.

Andy Jones, who is voting for Trump in Allegheny County, said television and radio ads, billboards and yard signs in western Pennsylvania are “out of control.” He describes it as a battle between his neighbors to see who can “outdo” the other in his yard.

“People here are definitely excited,” he said. “It’s an important state.”