Which states could delay how quickly the 2024 election is called?

(NewsNation) — In 2020, the presidential election wasn't called for four days due to the time it took to count ballots in states across the country. Four years later, several states could determine when the country will know whether former President Donald Trump or Vice President Kamala Harris has won the 2024 election.

Trump and Harris remain engaged in a too-close-to-call battle with two weeks remaining before Election Day. With the two candidates polling neck and neck in all seven swing states, election forecasters can envision several scenarios where the race could be determined in either hours or days, with possible legal challenges to follow.

Pennsylvania secured the White House for President Joe Biden in 2020 on the Saturday after Election Day.

The Keystone State has changed how it counts votes following delays in the 2020 election, but this year, Pennsylvania and other states like Georgia, North Carolina and Arizona could determine when we know who will become the next president.

“There are quicker paths, and then, there are dayslong paths,” said Drew McCoy, the president of NewsNation partner Decision Desk HQ.

Georgia again key to election results

Trump is targeting Georgia this cycle after Biden flipped the state blue for the first time in 28 years by a margin of 11,179 votes.

Election officials recounted the votes twice in 2020, each time reaffirming the original count in favor of Biden.

“We have now counted legally cast ballots three times, and the results remain unchanged,” Secretary of State Brad Raffensperger said after the third recount.

Trump allegedly called Raffensberger and asked him to find enough votes to reverse the results in his favor. The former president is currently charged in state court for trying to subvert the state's 2020 election.

This year, Georgia has already collected a record number of early ballots as both Harris and Trump continue to campaign around the state.

Despite the spotlight on Georgia, McCoy believes that the state could be among the first called on election night.

McCoy said Trump's easiest path to the presidency is flipping Georgia and Pennsylvania. If Harris can keep Georgia blue and win North Carolina, that dramatically changes the map, he said.

North Carolina early voting records

Trump won North Carolina by 1.3% in 2020, and four years later, and McCoy believes Trump needs to carry it again to win in November.

A Democrat hasn't won the state since former President Barack Obama in 2008, but polls have shown that Harris is within the margin of error with two weeks remaining before the election.

Like Georgia, North Carolina has experienced record levels of early voting despite residents trying to recover from widespread damage caused by the deadly Hurricane Helene.

By McCoy's estimation, Georgia and North Carolina could be called sometime between 10 p.m. and midnight on election night, which could set the stage for what happens in the rest of the country.

Will Pennsylvania's count be delayed again?

Pennsylvania state law does not permit mail-in ballots to be counted before Election Day, which led directly to the four days needed to determine a winner in 2020.

It became the epicenter of Trump's "Stop The Steal" campaign in which he alleged mail-in ballots that arrived after Election Day should not be counted.

The campaign mounted a series of legal challenges claiming that Republican observers were kept too far from the voting tabulation process in cities like Philadelphia, The Associated Press reported. A record number (375,000) of mail-in ballots were received in the state in 2020, with the majority of those coming from Democratic voters, according to CBS News.

Republican Secretary of Commonwealth Al Schmidt told CBS News that due to state laws, he believes the vote-counting process could still take time to ensure an accurate result. But since 2020, Pennsylvania has improved its vote-counting process as new machinery has been introduced that processes ballots more quickly, Schmidt said.

"Our counties are working night and day to count their voters' votes," Schmidt told CBS News. "They're doing so as quickly as they can and with integrity."

McCoy believes that while vote counting in Pennsylvania's 67 counties will require careful attention, he expects results to trickle in during the overnight hours and into Wednesday morning.

But he said the disparity between the state's Republican and Democratic areas could create some drama along the way.

“It’s not unexpected that there might be some changes in the lead over the course of the night,” McCoy told NewsNation.

Mail-in voting in Arizona

Arizona, where roughly 90% of ballots were mailed in during the 2020 election, historically takes longer to call due to the time it takes to determine which ballots can be counted based on the postmark.

Biden won Arizona by just 0.3% in 2020. Maricopa County, where much of the Phoenix metro area is located, is expected to garner the crux of the election attention four years after Biden won the county by 45,109 votes.

In 2020, after Trump claimed the election was stolen, Arizona Republicans commissioned a hand recount of Maricopa County's 2.1 million ballots, which affirmed Biden had defeated Trump.

Election experts expect another close race in Arizona, keeping interest in the state high.

Delays could push the race into a critical position if the state is needed to secure victory for either candidate.

Other factors on Election Day

Voter turnout could also help determine the timeframe for a winner, according to NewsNation political editor and "The Hill Sunday" host Chris Stirewalt.

Turnout numbers for the upcoming election should be known by 9 p.m. ET on election night, which could provide clues about which candidates could benefit most and when a winner will be determined.

Stirewalt also believes that the scrutiny around election officials in 2020 could spill over to this election, which might slow things down. He also expects legal challenges to be mounted again, which would also lead to delays.

With so many factors in play, establishing any sense of certainty proves to be difficult.

“If we’re going to be very honest, then we have to say we don’t really know,” Stirewalt told NewsNation.  “We have to be prepared for a really quick night or a long week, but we certainly can’t rule either of those out.”