Over the past few hours, Americans have been queuing at polling stations across the United States and casting their ballots in perhaps the most consequential election in a century.
The entire country and much of the world is watching, bracing to learn which candidate will emerge victorious: Republican President Donald Trump or Democratic nominee and former Vice President Joe Biden.
Watch: It's been one of the most polarising presidential contests in US history. Case in point...
Depending on a few key states, that could be clear by the time Australians go to bed, or in a few days' time. Few are willing to speculate with confidence — and little wonder, given how many polls got it wrong in 2016.
But let's give it a go shall we?
Mamamia's daily news podcast, The Quicky, called Chas Licciardello of ABC's Planet America to wade through some possible outcomes and just how likely they will be.
Scenario: Biden wins the popular vote, but Trump wins the presidency.
The electoral college system means that it's possible for a candidate to earn more votes from the public but not win the presidency, simply because those votes haven't come from enough different states.
(See our earlier article for a super simple explanation about how the electoral college works.)
It happened to Hillary Clinton in 2016. So could it happen again? Could Donald Trump win in enough small states to hit the magic 270 electoral college votes?
According to Chas, that would depend on the polls having made "a very big mistake". Because the polls in two key states are tipping firmly in Biden's favour.
"Essentially, for [Trump] to win the presidency, he needs to either win Pennsylvania, where the polling average is about five points to Biden; or he needs to win Minnesota, where the polling average is about seven points to Biden," he said.
Hang on. Polls were hugely mistaken last election. Couldn't that happen again?
"The polling errors in 2016 were about four points. There was one state with the six-point error, which was Wisconsin, but they basically hadn't polled in Wisconsin [prior to that election]," said.
According to Chas, things have changed. They've polled voters heavily in the key battleground states, so there's less likely to be a surprise result.