The election results in early 2024 may show trends that do not hold true. This is how you make sense of the count.

Seam polls close across six time zones on election night, millions will tune in to see who will be the 47th president of the United States. But the wait is likely to be long for a few reasons that may not be immediately apparent. Election results that looks like victory for a candidate at 22.00, could change the other way at 23.30 or even later. And it can take days to find out who won.

The reasons why election watchers might see sudden changes in the position of Kamala Harris or Donald Trump in the most competitive states are largely influenced by two factors: how absentee ballots are processed and the population density of an area.

That’s why CBS News’ live coverage will show its statewide modelsincluding exit polls and where there are outstanding votes.

The treatment of absentee ballots differs from state to state

It may seem quite straightforward – only seven battleground states considered to be in play in the election: Arizona, Nevada, Georgia, Michigan, Wisconsin, North Carolina and Pennsylvania, and these are the states that will likely decide the winner.

But each state has different rules for when absentee ballots can be processed and counted. In the early hours of election night, there may be an incomplete picture of who will win a state because absentee ballots will take longer in some states than others to show up in the count.

Arizona and North Carolina require all ballots to be received on or before Election Day, and both states allow ballots to be processed early, suggesting that election night vote totals should include many mail-in ballots early after polls close.

Michigan are among the states that begin processing ballots early and require all ballots to be on Election Day, so the ballots are likely to include absentee ballots.

Nevada also allows for early processing of absentee ballots, but ballots can also be received after election day; they must be postmarked no later than 5 November or received in the Electoral Department no later than 8 November if they do not have postmarks. In May, the Nevada Secretary of State issued guidance aimed at speeding up the publication of election results.

“Releasing results more quickly will increase transparency, help us fight misinformation and ease pressure on election officials,” Foreign Secretary Francisco Aguilar said in a statement at the time.

Early in-person and postal ballots may begin being counted at 8 a.m. PT on Election Day. At the latest at By 6 p.m. PT (9 p.m. ET) on Election Day, county clerks must provide their first election results to the Secretary of State, who expects to release unofficial results as soon as the polls close. Previously, no counting began until polling stations closed, according to the foreign minister.

Wisconsin and Pennsylvania both require that all ballots be received before Election Day, but they largely prohibit the processing and counting of absentee ballots until the morning of Election Day. Some of the postal ballots may appear in the initial results, but it will take some time for election officials to count those ballots. About 1.8 million people voted absentee in Pennsylvania this year.

In 2020, it was Pennsylvania that took over the presidency for Joe Biden, but the state did not have a projected winner until four days after the election. However, absentee voting was higher that year due to the pandemic. Also new this year, Pennsylvania requires that all ballots be submitted before Election Day. It no longer accepts ballots postmarked on election day and received within three days after.

In general, more Democrats have voted early than Republicans, although Republicans made a concerted effort this year to convince their constituents to vote by early voting. mail or early in person and they seem to have had some success. If they did, it will be despite the mixed messages from Donald Trump, who still speaks out against postal voting.

Election results for urban and rural districts

In the first few hours Tuesday night after the polls close, there may be a lot of red on the map for Trump and other Republicans, but that could be a function of population density.

Polling stations in smaller regions often tabulate and report results faster than their urban counterparts simply because there are fewer ballots to process. Across key battleground states in the 2024 presidential election, some of the biggest cities — population centers associated with heavy Democratic majorities — are expected to be among the latest to report full results, experts say. Fulton County, Georgia — home to much of Atlanta — “has a notorious reputation for being slow,” said Emory University professor Andra Gillespie.

“Fulton County is also the largest county in the state,” Gillespie said. “It’s not like a county that can flip after just 10,000 or 15,000 votes.”

“Notorious” is also how a professor in another battleground, Michigan, described the voting process in the state’s largest city.

“Detroit is notoriously slow,” said Oakland University professor David Dulio. And Warren, the state’s third-largest city, is also likely to be slower than other precincts because it chose not to pre-process absentee ballots. A new law allowed municipalities in the state to begin processing those ballots up to eight days before the election.

“They won’t have any of these absences addressed at all until Tuesday,” Dulio told CBS News.

Experts had similar warnings about election returns for major cities in Arizona, Wisconsin and Pennsylvania.

Milwaukee Election Commission Executive Director Paulina Gutiérrez recently told Wisconsin Public Radio that she expects the city’s results to come in after midnight.

“We are the largest city in the state of Wisconsin,” Gutiérrez told the radio station. “We follow the same laws that everyone else follows here in the state of Wisconsin. We just have a lot more to do.”

The Supreme Court on Friday overruled a ruling by Pennsylvania’s highest court, which requires officials to do so count provisional ballots made by voters whose postal vote was rejected. In a particularly close race, this can mean a significant delay.

The processing of these votes could follow a similar pattern and take longer in Philadelphia and other cities than in less populous regions, says University of Pennsylvania professor Marc Meredith.

“Provisional ballots are typically reported out in smaller counties Thursday, through Monday in the larger counties,” Meredith said.