US Election 2020: Tense wait as US election winner remains unclear

The outcome of the US presidential election is on a knife edge, with Donald Trump and his rival Joe Biden neck and neck in key swing states.

Mr Trump, a Republican, claimed to have won and vowed to launch a Supreme Court challenge, baselessly alleging fraud.

Earlier Mr Biden, a Democrat, said he was “on track” to victory.

Millions of votes remain uncounted and no candidate can credibly claim victory as yet. There is no evidence of fraud.

The US is on course for the highest electoral turnout in a century. More than 100 million people cast their ballots in early voting before election day, and tens of millions more added their vote on Tuesday.

With the nation on edge, the final result may not be known for days.

What are the results so far?

Mr Trump has defied the pre-election polls to do better than predicted, but Mr Biden is still in the race and the overall result is not yet clear.

In the US election, voters decide state-level contests rather than an overall, single, national one.

To be elected president, a candidate must win at least 270 votes in what is called the electoral college. Each US state gets a certain number of votes partly based on its population and there are a total of 538 up for grabs.

The president is projected to have held the must-win state of Florida – a major boost to his re-election bid.

But Mr Biden could snatch Arizona, a once reliably conservative state. Fox News and the Associated Press have projected Mr Biden will win that state and CBS News, the BBC’s US partner, says it is leaning the Democrat’s way.

A loss for Mr Trump in that previously Republican-voting state would be a potentially serious setback.

The Rust Belt battlegrounds of Pennsylvania, Michigan and Wisconsin – which propelled Mr Trump to the White House four years ago – are very close.

Pennsylvania is considered crucial for Mr Trump if he is to stave off defeat – he has a significant lead there but a large number of mail-in ballots are yet to be counted. Mr Biden has a narrow lead in Wisconsin and the two are almost neck-and-neck in Michigan.

BBC