(WASHINGTON) — While tens of millions of early votes have already been cast, there are still millions of Americans who will be heading to the polls on Election Day. Experts predict the 2024 election will be one of the closest in history, with several key states still in contention that could determine the next president.

Vice President Kamala Harris and former President Donald Trump have been actively campaigning over the past few months in several swing states. This year, seven swing states are in intense competition: Arizona, Georgia, Michigan, Nevada, North Carolina, Pennsylvania and Wisconsin.

To win the White House, a candidate needs 270 electoral votes, different combinations from the collective total of 93 electoral votes from these swing states will ultimately determine the winner.

Election Day is Tuesday, Nov. 5, 2024, with polling hours varying by state law. Here’s an update on three of the seven swing states in the final hours leading up to the election.

In Pennsylvania, young voters ready to make an impact

Pennsylvania, with 19 electoral college votes, is considered the key to the election and many believe the winner of Pennsylvania will become the next president.

In this battleground state, ABC News spoke with young voters who believe their vote could significantly impact this election. These voters have observed Harris and Trump competing often in their state.

Both candidates held many stops and rallies on Monday.

Two first-time voters, 18-year-old Isaac Gourley and Caleb Root, will be at one of Pennsylvania’s thousands of polling places. They attend Redbank Valley High School in Western Pennsylvania.

They have been listening to both presidential candidates and will decide their vote based on their priorities.

“What stuck out to me was just their — kind of like international — policy,” Gourley said. “You know, how we talk to other people.”

According to a Tufts University study, about 50% of registered voters 18-29-year-olds voted in the 2020 election — an all-time high. In Pennsylvania, they turned out at a rate even higher than the national average: 54%.

“I pay attention a lot to the economy,” Root said.

The rules for counting ballots in Pennsylvania indicate that it may take days to determine the winner. Mailed-in votes cannot be counted until polls open at 7 a.m. on Election Day.

Helene won’t stop voters in North Carolina

Despite initial concerns, voter turnout rates in the 25 North Carolina counties hardest hit by Hurricane Helene surpassed statewide early voting averages leading up to Election Day, with more than 760,000 total ballots cast.

North Carolina and its 16 electoral votes are especially crucial in the razor-thin contest between Harris and Trump. According to the latest NYT/Siena College polling, Harris has a narrow lead over Trump in a race that remains too close to call.

In this historic election that hinges on voter turnout, both campaigns are targeting women, the country’s largest voting bloc.

An ABC News/Ipsos poll shows a clear gender gap between voters. Trump is up 5 points with male voters, while Harris is up by 11 points with women.

During early voting, young women on the North Carolina State University campus marched to the polls with a pro-choice message, inviting men to join them.

“I’m really scared that I feel like I don’t know the rights I have as a woman,” Lizzie Pascal, a student there, said.

Harris leads suburban women voters nationally by 15 points overall; however, Trump has a four-point advantage among white women, according to the latest ABC News/Ipsos poll. That demographic is widely believed to have contributed to his victory in 2016.

Sandy Joiner, president of the Western Wake County Republican Club, has worked to canvass with Republican women competing for state and local seats.

“We have knocked on around 12,000 doors in our area,” Joiner said. “And we have, we have knocked all the doors, so we don’t have any doors left. So what we’re doing now is we’re knocking doors in areas that may not have been reached.”

The same goals drive these women, whether they are encouraging voters to turn out in storm zones, suburbs or on college campuses. Women are likely to hold the key to determining who ascends to the White House when all the votes are counted on and after election night.

How Michigan is a must-win for both Trump and Harris

Experts say Michigan is a must-win for both sides, which is why both candidates campaigned extensively across the Great Lakes.

Once part of the Democrats’ so-called “blue wall,” polling shows that Michigan — and its 15 electoral votes — is a tossup.

While early votes show an increase in women and young voters in college towns, one of the groups that was once solidly Democratic is no longer true blue: union members.

ABC News spoke with Douglas King, an autoworker and UAW member for nearly 30 years. He says the economy, like for so many other Americans, is his top issue.

“I was raised to believe that the Democrats are the party of the working people,” King said. “And maybe at one time they were. I don’t feel that way now.”

Many union leadership endorsed Harris.

In this tightly contested race, the more than 500,000 union workers are crucial for Harris; however, some of them appear to be moving away from voting for the Democratic Party. King, who voted for Barack Obama twice, has decided to support Trump for president for the third time.

“People are afraid to say they’re voting for Trump because Trump supporters are put in a box, that they’re these hateful, racist people that are homophobic, and it’s just not true,” King said. “Trump has a lot of support on the plant floor.”

There are cracks in the old coalition that has consistently voted for Democrats for the past 30 years. However, Trump broke through the blue wall in 2016 by narrowly defeating Hillary Clinton by roughly 10,000 votes in Michigan.

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