Election officials in the critical swing state of Pennsylvania are tackling thousands of last-minute challenges to mail-in ballots.

More than 4,000 mail ballot applications have been challenged in multiple counties.

State election officials said the mass challenges are focusing on ballots from overseas voters, and individuals with past mail forwarding requests.

So far, Chester and York counties have considered the claims and dismissed them, preserving those voters’ eligibility. However, any ballots from voters whose applications were challenged must be sequestered until election board officials hold hearings to decide voters’ eligibility — which must be done no later than Friday.

This comes as Pennsylvania will play a major role in the outcome of the presidential election.

With 19, the Quaker State has the most electoral votes of among all seven battleground states.

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Scripps News on the ground in Philadelphia witnessed voters lining up at polling stations before they opened Tuesday morning.

Pennsylvania has seen very tight polling margins in the last two election cycles. In 2016, former President Donald Trump won the state by roughly 50,000 votes. And in the 2020 election, President Joe Biden won the state by about 80,000 votes.

Democratic nominee and Vice President Kamala Harris spent the eve of Election Day campaigning around Pennsylvania, with her team also going door-to-door ensuring Democrats and independents knew where to vote. Her running mate, Minnesota Gov. Tim Walz, visited the state on Election Day.

Trump also stopped in Pennsylvania on Monday but also visited two other swing states — North Carolina and Michigan.

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