By dawn on November 4, 2016, Americans knew their next president would be Donald Trump. Four years before that, Barack Obama’s re-election was confirmed shortly after midnight when victory in Virginia gave him the required Electoral College votes. But, as sunrise approaches in the US on November 4, 2020, there is still no clear winner. Why? Close races and the sheer number of postal ballots mean Americans face a days-long wait for the final outcome. Even then, legal challenges could delay things further. Ballots sent in by post have become the focus of this election simply because of the number of voters who chose this method. In 2016, 33 million votes were cast by mail. This year, about 64 million postal votes were cast – although some states have yet to give final counts. Many states made voting by post available for the first time because of the risk posed by voting in person amid the coronavirus pandemic, which has killed more people in the US than anywhere else. The millions of votes mailed in before Election Day are slowing the calculation of results for both practical and procedural reasons. Voting in person differs from state to state but in some places it is done electronically, while elsewhere it’s on a paper ballot that can be quickly sorted, tabulated and counted. By contrast, postal ballots require envelopes to be opened and signatures to be checked, which means they take longer to tabulate. And while some states processed postal ballots as they were received before Election Day, meaning they were reported alongside those cast on November 3, others started only after polls closed on Tuesday night. Then, there is the problem that some votes are still coming in, despite the polls having closed. The Supreme Court has ruled that postal ballots will be accepted up to three days after the election as long as the postmark is on or before November 3. President Donald Trump and his Republican party have vowed mount legal challenges on the eligibility of such votes, raising the prospect of further delays to the election result. Mr Trump repeated the threat in a speech claiming victory overnight, even though results from key states such as Pennsylvania, Michigan and North Carolina had yet to become clear. Both Mr Trump and his Democratic rival, Joe Biden, have more than 200 Electoral College votes but are still short of 270 needed to win. The result in Pennsylvania, with 20 Electoral College votes, could be the most belated as mail-in ballots were only opened on Election Day and counting was stopped overnight, unlike some states where officials pressed on to get the results out as quickly as possible