US election results 2020: When might we get a winner?

Okay, so who is going to be the next president?
We still don't know, because not enough votes have been counted for either Donald Trump or Joe Biden to have secured victory.

People gather in Times Square as they await election results on November 3, 2020 in New York City
IMAGE COPYRIGHTGETTY IMAGES
We're into our second day of counting. The huge number of postal votes cast during this pandemic election and different states' laws about how to count them, meant this always was going to take longer if the result was close.

And it is.

Hasn't Joe Biden won the popular vote?
Yes, so far, but that's not what decides who gets to be president.

Instead, a candidate has to win the majority in a system called the electoral college, where each state gets a certain number of votes or "electors" roughly in proportion to its population. If you win a state, you win all its votes (except Nebraska and Maine, but that's complicated). There are 538 state votes and the person who gets 270 wins the prize.

But why is it taking so long?

This is partly down to how individual states are counting and the order in which they count different types of votes (for example postal votes). Let's break it down to what's happening in some of the battlegrounds:

Arizona (11 votes): Joe Biden has a narrowing lead with about 500,000 votes still to be counted, local media report. More than half of those are from Maricopa County, home to 60% of the state's population - it will post more results at 19:00 local time.

Nevada (6 votes): Mr Biden has a very narrow lead. The state government posted FAQs saying counting is going at the expected pace, a timeline set by Nevada law. Postal votes haven't yet been counted, and updates will come in the morning, with unofficial results here.

Georgia (16 votes): Mr Trump has a very narrow lead over Mr Biden in Georgia, where the secretary of state has said the vote should be complete by midday Thursday.

Pennsylvania (20 votes): In Pennsylvania, there are more than 580,000 mail ballots left to count - that's because state law says postal ballots can't be counted before election day. Mr Trump leads Mr Biden so far, but because mail ballots tend to go Democratic, analysts say anything is possible.

Wisconsin (10) and Michigan (16): The BBC projects that Mr Biden will win Michigan and US media have projected him to win in Wisconsin, where he leads by less than 1% of the vote.

Why does it have to be so hard?
Unlike some other nations, there's no one body or election commission that oversees elections in the US. Each state makes its own laws and systems for counting votes.

So is it just maths now?
If Mr Biden gets Nevada, Arizona and Wisconsin in addition to Michigan, he gets his 270 votes. Mr Trump will need Pennsylvania's votes and to win three states out of Georgia, North Carolina, Nevada or Arizona. But Mr Trump has launched legal and other challenges such as:

Seeking a recount in Wisconsin
Seeking to halt a vote count in Michigan because Republicans say they need more transparency
Challenging the extension of mail ballot deadlines in Pennsylvania
Challenging late absentee ballots in Georgia
With the exception of Pennsylvania, where the Supreme Court previously hinted it could revisit the rules, analysts suggest most of these concern small numbers of ballots that might not make a difference in the end.

Poll workers in Michigan
IMAGE COPYRIGHTGETTY IMAGES
image captionPoll officials in Michigan - now called for Biden - work to tally ballots
But really, it's not just maths
It now looks like polling data going into this week didn't tell us the whole story about the American public. Many observers didn't realise the race would be so tight.

Robert Cuffe, the BBC's head of statistics, says it's still too early to say whether this election has been a pollster's nightmare. Final national polls showed Mr Biden leading Mr Trump by about eight points. In battleground states Mr Biden also polled in the lead, but by a much slimmer margin.