A version of this story appears in CNN's What Matters newsletter. To receive it in your inbox, sign up for free Here.

CNN
—

It was called the “red mirage” or the “blue shift.”

This is the latest phenomenon in which an apparent Republican lead early after election night is wiped out by the counting of mail-in ballots later that evening or in the days following Election Day.

Former President Donald Trump pointed to the red mirage to support his baseless claims of voter fraud, when in reality it was due to the increase in mail-in voting and the often peculiar rules about when those ballots can be counted.

As most Americans went to bed on election night in 2020, November 3rd, The end result was anything but clear.

The contest between then-President Trump and now-President Joe Biden was too early to include the key states of Arizona, North Carolina, Nevada, Wisconsin, Michigan, Maine, Georgia and Pennsylvania.

Dramatic hours were spent in the following days watching the counting of votes in these states. The vote count did not reflect a Biden lead in Georgia until the early morning of November 6, when, as CNN's Phil Mattingly showed viewers on the Magic Wall, small amounts of votes were counted and impacted the very close election.

CNN was able to predict that Biden would win the election four days after Election Day, on November 7, but counting would continue. An analysis by researchers at the Massachusetts Institute of Technology found that counties won by Biden counted slower on average than counties won by Trump.

There was also a blue shift in 2016, but it was not decisive. As CNN's Marshall Cohen wrote, Hillary Clinton was still behind in the popular vote when she made her concession to Americans and admitted defeat the day after Election Day. Although the number of ballots cast was not enough to secure her entry into the White House, it was more than enough to give her a lead over millions of ballots in the popular vote.

In 2020, the states with the lowest counts were places like California, which lean heavily Democratic and where every voter is registered a postal ballot will be sent. That means there could still be a blue shift in the popular vote, even if it doesn't delay the determination of the presidential election results.

It's important to remember that while news networks like CNN will predict a winner when it's clear who will win, the races aren't officially confirmed until later. Certification deadlines vary from state to state, but all have until December 11, 2024 to complete recounts and resolve disputes if necessary Presidential results.

There are indications that things could move faster in some key states.

In Georgia, a new election law means more people will vote sooner in person rather than by mail, which could speed up the counting of mail-in ballots. North Carolina will no longer accept mail-in ballots if they arrive after Election Day.

The Brennan Center for Justice, which tracks election-related legislation, has a list of potential bottlenecks.

Georgia Secretary of State Brad Raffensperger, a Republican, recently said on CBS' “Face the Nation” that he expects the vast majority of ballots to be processed and counted in the hours after polls close.

“All early voting and all early accepted ballots must have their results declared by 8:00 p.m. That’s 70, maybe even 75% of all votes cast, which will be announced no later than 8 p.m. on election night,” he said. But if Georgia's 2024 election is as close as it was in 2020, the outcome may still not be clear.

Raffensperger was asked if it could take a week to determine the winner in Georgia.

“Absolutely not,” he said. “What we will be waiting for are the foreign ballots, which will arrive by Friday at the latest, and then those will be the final numbers. And we’ll just see if that makes a difference in the total number of votes.”

Fareed explains why we are experiencing a political realignment

Other states, such as key battlegrounds Pennsylvania and Wisconsin, have not allowed election officials to process ballots before Election Day. But even there, the count could be faster, with more experience and fewer ballots compared to the pandemic-era 2020 election. The Center for Election Innovation & Research provides an overview of the various rules and deadlines for processing mail-in ballots.

In Michigan, another key state where ballot processing can occur before Election Day, CBS Secretary of State Jocelyn Benson was also asked how long it will take to count ballots. Benson, a Democrat, said she hopes to know the result by the end of Wednesday, Nov. 6. one day after the polls closed.

“We will always prioritize accuracy and safety over efficiency,” she said.

If margins are tight, it can still take days.

Pennsylvania's top elections official is Republican Al Schmidt, who recently told NPR that people need to trust the system in the period after polls close.

“In 2020 … we viewed the window between the polls closing at 8 p.m. on election night and the race being called as a time of vulnerability in which people sought to undermine confidence in the results,” he said, pointing out In the end, after all the votes were counted, the results in Pennsylvania were not that close.

The upcoming election may take some time, as anyone old enough to remember the year 2000 can attest. A close election in Florida involved a flawed punch-hole voting system that led to some “hanging guy” ballots being up for debate.

This year's election outcome dragged on for more than a month – 36 days until the U.S. Supreme Court stopped a partial recount in Florida, essentially handing the election to George W. Bush. Then-Vice President Al Gore conceded on December 13 and then became one of only three vice presidents to oversee the counting of electoral votes in their own defeat. Harris could be the fourth. Or the first since George HW Bush to oversee their own victory.

Just as no one knows who will win the 2024 election, it is also not entirely clear how long it will take to determine the winner this year.