Americans have two big questions as they face another election with a deeply divided electorate: Who will win, and when will they know?

In 2020, election week replaced election night: Joe Biden was only declared the winner on Saturday. This year it could go either way. It could take a week for the NBC News Decision Desk to announce a presidential winner, but it could happen as early as Wednesday, even Wednesday morning.

The truth is that the Decision Desk cannot know what scenario will unfold until election night, no matter how carefully we have analyzed the polls, early voting, and other election-related data. The answer depends not only on how states count their votes, but also on the unknowable factor of how small the margins will be.

One thing is clear: the days of proposing a winner on election night itself are almost certainly over.

If we were to predict a presidential winner on Wednesday, it would require that the key battleground states, especially Pennsylvania, not be substantively connected. There must be a large enough spread between first and second place to predict a winner.

In close races, such as the 2020 presidential race in Georgia and Arizona (Joe Biden’s margins of victory in these states were 11,779 and 10,457 votes, respectively), essentially all votes must be counted before NBC News’ Decision Desk makes a proposal can do. winner. This can take days.

But let’s go through the battleground states where Wednesday call-ups are at least possible.

How the critical ‘blue wall’ states are counting their votes – and how this is different from 2020

Any path to winning the White House will likely go through the “blue wall” states of Pennsylvania, Michigan and Wisconsin. In 2020, Pennsylvania was the central Electoral College state that assumed the presidency, and there is a good chance it will play that role again. But in 2020, it took four days after Election Day for the NBC News Decision Desk to declare a winner.

This may happen much earlier this year. This is because 98% to 99% of votes in Pennsylvania will likely be counted by Wednesday morning.

How Pennsylvania counts its votes remains largely unchanged since 2020, but the process should be more efficient this year. Key counties like Allegheny (home of Pittsburgh) and Philadelphia have invested heavily in new voting machines and added more staff to help process ballots. Also remember that this election is not taking place during a global pandemic that required strict social distancing among election officials, delaying the count.

We expect several Pennsylvania counties to release large numbers of early votes shortly after polls close, followed by in-person voting on Election Day. This would allow the first votes received on Election Day, along with provisional ballots, to still be counted on Wednesday.

If 99% of the total votes are counted quickly, a Wednesday projection in Pennsylvania is entirely possible unless the race is razor-thin. In 2022, we had about 90% of the votes counted in Pennsylvania when, at 12:51 p.m. ET, the NBC News Decision Desk projected Democrat John Fetterman as the winner of the state’s Senate race.

In Wisconsin and Michigan, the bulk of votes could also be counted by Wednesday if previous reporting patterns hold.

Based on these patterns, Wisconsin’s count should be well over 99% by Wednesday morning. In Michigan it should be more than 95%. An important note in Michigan: For the first time, municipalities with more than 5,000 residents can begin pre-processing absentee ballots (opening envelopes, verifying voter signatures, etc.) several days before the election, which could lead to a more efficient counting of the ballots. elections. night.

On the other hand, the introduction of early in-person voting in Michigan could pose some problems in quickly counting votes. Regardless of these changes, both Michigan and Wisconsin are counting almost all of their votes quickly. So unless the races are extremely close, there’s a good chance the NBC News Decision Desk will be able to make a projection sometime on Wednesday.

However, if the races are this close, it could take days or maybe even a week depending on the margins.

How the Sun Belt battlegrounds count their votes

Outside the blue wall, the critical swing states of Georgia and North Carolina are among the best in the country when it comes to efficiently processing and counting their votes.

These two states are also extremely good at making their data available to the public electronically. In Georgia, more than 99% of the votes will be counted on election night. In fact, almost all votes in recent elections were counted by 1 a.m. ET. However, Georgia was so close in 2020 that it took days for the race to break down.

North Carolina has a similar pattern in how it reports votes: In previous elections, 99% of votes were counted by midnight. Still, any chance of an election night projection in any of these closely divided states depends on a wide enough spread between the two candidates.

The single electoral vote awarded to the winner in Nebraska’s 2nd Congressional District could also be critical on the road to 270. Without significant changes to how votes are counted in Nebraska, about 90% can be expected to vote by Wednesday morning of the votes will have been counted. , which again could lead to a projection if there is sufficient spread between the candidates.

The last two battleground states, Arizona and Nevada, will almost certainly not be mentioned anytime soon. If the presidency comes down to one of these states, forget all thoughts of a Wednesday resolution.

In 2020, NBC News did not project a winner in Arizona until November 12, nine days after Election Day. And unlike some other nearby states, it wasn’t just because the margin was so small.

Normally, Arizona has as much as 20% of votes left to count after election night, especially late-arriving ballots. And there are very substantial differences between Republicans and Democrats when it comes to who votes when (early versus on Election Day). This makes it nearly impossible to declare a winner on election night in Arizona.

Nevada is a state with a lot of early voting, both absentee and in-person, that isn’t counted on election night. In the past, almost a quarter of votes had still not been counted by the Wednesday morning after election day.

Given that the state has historically been close to presidential elections, the chances of a close race with a large number of uncounted votes are very low.

The bottom line: In Arizona and Nevada, it will likely take a few days, maybe longer, to know the winner.