Mr Biden has been holed up in Delaware as he prepares intensively to face the president, with former Hillary Clinton staffer Philippe Reines stepping into an oversized suit to stand in for the looming incumbent. Mr Trump, meanwhile, has reportedly been preparing by glancing at videos and flash cards on Air Force One as he buzzes between freewheeling campaign rallies.
But whether the event much matters will ultimately rest on what the two men are asked. Here, the Independent’s writers and editors lay out their own questions.
Ben Chu, Economics Editor
The exposure of Mr Trump’s astonishing tax returns fits perfectly with a grim American reality: income inequality in the US has exploded over the past half century.
In 1980, the richest 1 per cent of Americans were taking home 10 dollars of every 100 dollars earned in the economy, and owned a fifth of the country’s wealth; today, those at the top are enjoying double that – 20 dollars out of every 100 dollars earned – and today, their share of the wealth has swollen to more than a third.
This surge in inequality has occurred under presidents of both major parties. Some argue that it flows inevitably from unavoidable economic forces which favour people with higher skills, such as technology, or the globalisation of the economy. But other rich and prosperous countries which are also subject to these forces have done a much better job of keeping inequality down.
So why has the US diverged? For a start, as Mr Trump’s now-unearthed tax returns show, other countries have taxed the rich more and redistributed income to the less well off.
America takes the lowest share of national income in taxation of all the countries in the G7 – just 24 per cent. That compares with 33 per cent in Canada, which is the next lowest. And whereas many developing countries are taking more in taxation to fund health spending for their ageing populations, the American government has been going the opposite way, granting ever more tax cuts to its richest people.
So, to the candidates: what will you do to address spiralling domestic inequality? Will tax and redistribution play a role, as they do in every other rich country – and if not, how will it be done?
Robert Fisk, Middle East Correspondent
Since the Middle East regularly damages the US presidency (see Carter, Reagan, Bush junior), it’s the one wound in the world that needs America’s constant attention – but since Mr Trump regards the region as a playground for Israel’s power and security and the Palestinians as unworthy of compassion, post-election America is going to have problems with it whoever wins.
Either Mr Trump continues to plaster his “peace of the century” over the Arabs and continues to join Sunni leaders in their conflict with the Shiites of the Middle East, or Joe Biden has to rewrite the history of the past four years and pretend they never happened.
Which he cannot do.
The US embassy will stay in Jerusalem, Gaza will remain under siege, and – worse still – Mr Biden would almost certainly turn to the same group of weary, generally pro-Israeli ‘peace’ experts who consistently failed his predecessors. Re-embracing the Iranian nuclear deal will be humiliating enough for any US president, and Mr Biden would need the EU to help him. Rekindling the broken Oslo agreement with Arafat’s pitiful successor is going to need the help of others. The EU again.
And most important of all – and here we come to the awful equation which Biden will have to recognise – he’s going to need the help of Russia. To re-imagine any kind of Palestinian state needs Putin’s support. To resume any kind of trust with Iran needs Putin’s help. To end the Syrian war needs Putin’s cooperation. If Biden can face all this in his first months, then he has to invite Putin to Washington or fly the presidential jet to Moscow.
But should the present crackpot remain in the White House – legally, at least – Mr Trump doesn’t have to do very much at all. Support Israel right or wrong, cow-tow to the wealthiest Gulf Arabs, betray old allies like the Kurds and ignore the colonisation of Arab land, overlooking the permanent breach of international law which this constitutes. And if Trump has any problems with that, he can always call the UK prime minister for advice.
To Mr Biden, then: How can he hope to control Israel when, for the entire Trump presidency, it has largely written, organised and produced the US’s Middle East policy – if Mr Trump ever had one?
Eric Lewis, Independent Voices
The rule of law has been under siege for four years now, with Mr Trump working mighty hard to turn our justice system into yet another cynical clown show.
The federal courts have been packed with highly ideological and marginally qualified judges, culminating in the hypocritical minute-to-midnight nomination to fill the seat of the legendary Ruth Bader Ginsburg, while the Attorney General declares himself only the “hand” of the President, in whom all prosecutorial discretion supposedly resides.
Thus, the rule of law has become another theater of hyper-partisan politics, a system where you help your friends and hurt your enemies.
There is something quite mundane, even conservative, about fealty to the rule of law. It can lead to results that we may not like. It can be slow and technical. The law is often a lagging indicator of social change. But without a reliable infrastructure to uphold neutral justice, the legal system becomes not just irrelevant but a tool of coercion and oppression.
As one great lawyer, Barack Obama, said in tribute to another, Ruth Bader Ginsburg: “A basic principle of the law — and of everyday fairness — is that we apply rules with consistency, and not based on what’s convenient or advantageous in the moment." Now more than ever, a commitment to be bound by enduring principles rather than tribal passions may determine our survival as a nation.
I would therefore ask each candidate: Are you committed to restoring the independence of the judiciary and the Department of Justice and their insulation from political pressure by the executive?
Michael Arceneaux, Independent Voices
Breonna Taylor’s killers were let off the hook precisely 65 years since Emmett Till’s killers were acquitted. So it should be obvious that today’s most pressing question regarding racial justice in America is still the most fundamental: do Black Lives Matter?
Mr Trump’s answer has been clear even before he became president. See his policies on renting to Black people and the Central Park Five.
The only candidate who will even entertain the question with any real seriousness is Joe Biden. But even if he has my vote, surely even his most ardent supporters can understand how depressing it is for some of us to only have the author of the 1994 Crime Bill to look to in hopes of righting the wrongs of America’s longstanding two-tier justice system. But alas, we must deal with today and save our worries for tomorrow.
Still, with a belligerent bigot as president further stoking racial flames and a justice system stuck in the status quo, Biden can’t simply say that Black Lives Matter. He must articulate a vision and a path to prove it.
So to Joe Biden, I ask: What three things are you going to do in the first 6 months of your presidency to prove you're serious about proving Black life matters in America?
Andrew Naughtie, Inside Washington Editor
If America’s twin crises of the coronavirus pandemic and ensuing economic calamity have really become chronic crises demanding sustained attention, there’s also an acute crisis brewing: Mr Trump’s refusal to guarantee a peaceful transfer of power, and his increasing insistence that the election (which he is currently likely, though far from certain, to lose) will be stolen from him.
Many Americans are rightly terrified at the prospect of a defeated president fighting dirty to stay in power and – tacitly or otherwise – encouraging armed and violent factions to defend his presidency. But many others will have written off the possibility as a fantasy, the feverish nightmare of a hyperactive political pundit class who thrive on drama.
The president, however, is making it clearer by the day that he has no intention of going quietly. And yet, he is not widely expected to win – and given Mr Biden’s solid national lead, there remains a possibility that Mr Trump loses so badly on election night that the mail-in ballots he disdains will only add to his defeat.
It needs to be made clear as quickly as possible what the president might actually do – whether he really is so committed to winning that he simply cannot conceive of any way he could “legitimately” lose, and what he might do if he is in fact roundly defeated on the night.
So the question to the president: are there any circumstances at all in which you would fully and unambiguously accept that you have lost? And to Mr Biden: If Mr Trump loses but refuses to leave the White House and claims you are launching a coup against him, what will you do about it?