On November 3, Americans go to the polls to elect a president and members of Congress. The focus will be on whether it will be President Joe Biden, and Kamala Harris as his vice-president, or the incumbent, President Donald Trump and Mike Pence as his vice-president. It will be a momentous election. Nobody thinks it is anything other than one of the most important in our time, not just for the United States but for the rest of the world, including Australia.
What time does it all happen?
The United States spans many time zones - Hawaii is six hours behind New York - so the polls don't all close at the same time.
But polls start to close from early evening on the East Coast which means that through Wednesday morning in eastern Australia we should get indications of how voting has gone. Swings or their absence should emerge. All-important Florida, for example, closes at 7pm which is 11am Newcastle time. Each state starts counting and a running total builds up. When the US TV networks think a candidate's lead is unbeatable, they "call" the result for one candidate or the other.
A complication this time
By Monday, more than 91 million Americans had voted either by post or in person at drop-off points. That's two-thirds of the total who voted in 2016. Democrats think early voting helps them. They may or may not be right. The Reuters news agency said on Thursday: "Across the 20 states that publish the party registration of early voters, more than 17.4 million registered Democrats had voted by Wednesday compared with 10.8 million registered Republicans."
Early voting may prolong the count. Some states count as votes come in and others count from the close of voting. It also increases the possibility of contention. There is already a lot of dispute about how to deal with votes posted before polling day but which arrive after it. Reuters cited "unfounded attacks from Trump who says the system is plagued by widespread fraud".
But US elections don't depend on the national total
The winning candidate needs to win enough states. Each state casts votes in the "electoral college" and how many votes it has depends largely on its population. To win the White House, 270 electoral college votes are needed. In 2016, the election was called for Donald Trump at about 8.30 in the evening in eastern Australia. Victory in Wisconsin put him over the 270 electoral votes needed.
So we'll know on Wednesday evening?
Not so fast. If it's close, the result may not be known for weeks. In 2000, it took a month for the winner in Florida to be declared, and whoever won Florida won the election. There were recounts and ultimately a decision by the Supreme Court. If the result is clear and the margin wide, we should know who has won by Wednesday evening. If the result is close, bring a sleeping bag.
Which states might be interesting?
The election will be decided in a few states. New York and California will opt for Mr Biden. Mississippi and Kansas for Mr Trump. And Texas? Amazingly, Texas may be in play. Mr Trump's lead in the polls has been thin in the Republican heartland so it may just provide an upset - probably not, but interesting. You can tell where the campaigns think the doubt is by where they have spent their time and money. And those states are Florida, Pennsylvania, North Carolina, Michigan, Wisconsin and Arizona.
According to National Public Radio, about nine out of every ten dollars spent on TV adverts have gone to those six states, all of which Mr Trump won in 2016. If Mr Trump loses Florida, it's all over for him.
Is the election just for president?
No. Voters will also choose members of the House of Representative and the Senate - the two bodies which make up Congress. Democrats already control the House. Republicans control the Senate. All 435 seats in the House are up for election this year, while 33 Senate seats are being voted on.
Who is going to win?
The polls have consistently given Mr Biden a lead nationally - but they gave Hillary Clinton a national lead in 2016. The most respected organisation in these matters, FiveThirtyEight, said: "We're way past the point where a normal polling error alone could hand Trump the win. Still, Trump has a meaningful chance, per our forecast - a little worse than the chances of rolling a one on a six-sided die (singular of dice)."
What can be said with more certainty is that it will be contested up until the last decision and even afterwards. The US Supreme Court may ultimately become involved. It now has a 6-3 conservative majority.
Lawyers are ready. It might not be clean.
