As the world's most enthralling recruitment process reaches its denouement, maybe it is worth carrying out a thought experiment.
Let's imagine you are running a small business — a fast food franchise, for the sake of topicality — and recruiting a new manager. What would be the red flags in considering applicants for the job?
Maybe the fact the candidate is a convicted felon, with three outstanding criminal cases still awaiting judgement, would be cause for concern. Perhaps a long history of racism would be a deal-breaker — including a recent false claim that members of a local immigrant community were eating cats and dogs.
Surely the applicant's misogyny would count against him — especially the video which came to light showing him boasting about sexually molesting women, and the civil litigation which found him liable for sexual abuse. Calling his main rival for the job "shit", a "dummy" and "mentally disabled" speaks of his deficiencies rather than hers.
An applicant with that kind of record and resume would struggle to get offered a day shift overseeing the drive-thru, still less a low-ranking managerial position. Yet with little over a week to go before election day, Donald Trump stands a strong chance of being rehired for the most powerful job on the planet.
His role in the January 6 insurrection has not been disqualifying. His autocratic tendencies — General Mark Milley, the former chairman of the Joint Chiefs of Staff, has called him "fascist to the core" and "the most dangerous person in the country" — are not disqualifying. His bizarre behaviour — such as dancing for 39 minutes at a recent town hall event in Pennsylvania, or rhapsodising about the dimensions of the golf great Arnold Palmer's genitalia — is not disqualifying.
Trump is seen as a saviour, not a sinner
Once again, we are reminded of that Trumpian truism uttered in 2016 on the eve of that year's Iowa caucus: "I could stand in the middle of Fifth Avenue and shoot somebody, and I wouldn't lose any voters."
Since then, he has stood in the middle of Washington DC and implored his supporters to march on the US Capitol to block the certification of an election he clearly lost, without relinquishing his status as party lodestar and figurehead. Purged of strident internal critics — such as the former congresswoman Liz Cheney, who is campaigning for Kamala Harris — the Republican party has become even more of a personal movement.
That Trumpian truism from 2016 is often explained by what has become an analytical cliche. The former president's outlandishness is baked in. Voters have come to expect it. But that deflects the question of why Trump's candidacy comes coated in so many layers of teflon rather than answering it.
His political viability is worth re-examining, not least because "the Fifth Avenue phenomenon" is even stronger now than it was in 2016. Millions are ready to accept the terms and conditions of "Trump 2.0".
First, it worth stating the obvious. For MAGA diehards, the very fact that Trump is prepared to say the unsayable, and to act in such a norm-busting manner, is central his appeal. To them, the prosecutions are a politically-motivated witch hunt. The events of January 6 have been blown up out of proportion. Polling at the start of this year showed that seven out of 10 Republicans thought too much was being made of the attack on the US Capitol, and that it was "time to move on".
Likewise, what seem to be paradoxes aren't that paradoxical. Often the question is asked, for example, why Trump, a thrice-married divorcee alleged to have had an extra-marital affair with a porn star, enjoys the support of so many white evangelicals, 80 per cent of whom supported him in 2020.
Yet Trump pulled off what none of his three Republican presidential predecessors succeeded in doing: the holy grail of altering the ideological composition of the Supreme Court so that Roe v Wade could finally be overturned.
America's mega-churches, moreover, have for decades had a MAGA vibe. Anyone shocked that Trump should find a loyal congregation in their pews has not been watching Christian cable channels. Besides, some of America's most popular TV evangelists have been mired in scandal, including Jim Bakker, Jimmy Swaggart and Jerry Falwell Jr, without being permanently dislodged from their thrones of grace.
But again, many white evangelicals do not look upon Trump as a sinner. They see him as a saviour.
Nostalgic for the Trump economy
The backing of prosperous, college-educated Republicans, who often baulk at Trump's vulgar behaviour, is also easily explained. Many have been seduced by the tax cuts he is promising. Many are nostalgic for the Trump economy, when mortgage rates and gas prices were lower. Many have reconciled themselves to the fact, and rationalised it in their minds, that his policies come with his personality.
As for Trump's historically high levels of support among African-Americans and Hispanics, there are multiple rationales. The economy. The fact that many Hispanic and Black voters respond positively to Trump's hardline stance on immigration, despite his demonisation of Latino and Haitian immigrants. The sales pitch from Trump that Democrats have taken for granted the Black vote especially, and not repaid that loyalty by delivering significant gains in living standards.
It is also worth bearing in mind that around 10 million Latinos are evangelicals, many with a devoutly Christian nationalist bent — a reminder that ethnic voting blocs are by no means monolithic.
For historical explanations of Trump's continued political viability, there is a 250-year backstory to mine. Americans have long gone a little weak-kneed at a strongman as president. Figures such as the demagogic ultra-nationalist Andrew Jackson, who Trump came to regard as his presidential kindred spirit. Conspiratorialism, of the kind promulgated by Trump, was present at the creation, when George III was cast as the anti-Christ.
Or we could travel back to the more recent past. President Bill Clinton, during his scandal-prone eight years in office, not only normalised presidential misconduct but produced the playbook on how to survive it.
Clinton cleverly reframed the question at the heart of every scandal, switching it from "who is right or wrong?" to "which side do you want to win?" By doing so, he tapped into the tribalism of politics at a time after the end of the Cold War when Washington was becoming more aggressively partisan.
LoadingThe rise of negative partisanship
Trump has thrived on, and fuelled, that same tribalism which, since the turn of the century, has become more zealous as elections have come to be fought on questions of culture and identity as well as economics and foreign policy. Indeed, in this era of extreme polarisation, the former president has benefited from one of the most pronounced trends in US politics: the rise of negative partisanship, where political behaviour is determined not so much by affection for your own side as animosity towards your opponent.
In 2016, Donald Trump won partly because he was Donald Trump — an anti-politician who promised to shake up Washington. But much of his appeal stemmed from the fact he wasn't Hillary Clinton. Part of the reason why Joe Biden won in 2020 was because Trump found it harder to portray him as a hate figure. Negative partisanship was not so guttural and impassioned.
Trump is trying to repeat the same trick with Kamala Harris that he pulled off with Hillary Clinton, by attacking her personally and also by assailing what he claims she personifies. A woke America. An elite America. A more multi-cultural America, in which minority groups will by mid-century be in the majority.
For many Americans, Trump is a bulwark against a future they do not want to live in. The phrase "Make America Great Again" recalls a bygone age.
For both sides, negative partisanship could be the key to victory. Harris is trying to draw together an anti-Trump coalition, including Republican defectors who fear the former president poses a clear and present danger to democratic norms.
Trump is trying to assemble an anti-Harris coalition, including Republican waverers who fear the vice-president poses a clear and present danger to what they would regard as cultural normalcy.
It explains the ugly tenor of the 2024 election, a contest driven by fear and mutual loathing.
Nick Bryant, a former BBC Washington correspondent, is the author of The Forever War: America's Unending Conflict with Itself.