This TV debate between Donald Trump and Hillary Clinton will decide the future of the free world

Given its potential to decide if Donald Trump assumes the leadership of the free world, the imminent presidential debate feels like a fairly significant TV event.

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For those unfamiliar with ironic understatement, I should translate. In this context, “fairly significant” means “the single most crucial event in the global history of television”. If that looks like hyperbole at first glance, take a second glance, a third, and as many as you need to cite a rival to the New York meeting of Trump and Hillary Clinton at 9pm (their time) on Monday night.

Since that 11 September footage of Hillary being unable to move her right leg, her national lead has shrunk to within the margin of error. The momentum has been with the tangerine huckster, who now has the edge in various swing states, most alarmingly Ohio. With the election result in the balance, this debate clearly has the capacity to determine whether Donald J Trump takes possession of the nucl…

But no, I’ve made a solemn vow not to fall back on that shorthand. Trotting out “the codes” is as lazy and cliched a tactic as adducing Hitler. It is also a statement of the bleedin’ obvious. Everyone knows the US President has the power to order the use of nuclear missiles, because the only human in history ever to give such an order was a US President. Recalling that Harry Truman was among the saner Oval Office occupants, it seems indelicate to contemplate that Trump, who would not be, may have that power in January.

With a record debate TV audience of 100 million Americans anticipated, Don King would confirm that this fight needs no gimmickry to shift tickets. The one Donald on earth with more certifiable hair than the boxing promoter obviously disagrees, to which end Trump has offered a ringside seat to a one-time mistress of Bill Clinton.

Gennifer Flowers has accepted his kindly offer, though it is not clear whether she will actually attend. Yet however tempting it is to use this conundrum as a distraction from the pre-bout tension, there are grander questions to consider.

Will Trump indulge his penchant for witty epithets by addressing his opponent as “Crooked Hillary”, or will he play it chivalrous with an overdue stab at appearing presidential? Will Hillary avoid coughing fits and retain motor control at all times? Can she project the wit and warmth she reportedly shows in private, or bore viewers into the Trump camp with overly detailed, robotically delivered answers?

Will he have taken the trouble to memorise some faintly coherent policy positions, or rely on the trademark stream of semi-consciousness that allows him to drift between rambling and often conflicting observations several times per sentence?

Will the moderator, Lester Holt, correct Trump’s most blatant whoppers, or leave the fact-checking to Hillary? Do enough voters care about facts in this post-objective truth era for that to make a difference?

What lasting difference debates make to voting patterns is itself a familiar point of debate. Some doubt this, though at this point in the quadrennial cycle others automatically cite Richard Nixon’s sweaty top lip, Gerald Ford’s proto-Trumpian ignorance of Soviet dominance in eastern Europe, Al Gore’s wretched pseudo-machismo against Dubya, etc, as evidence that they can influence close races.

This age of wonderment is no time to strike a tone of certainty about that or anything else connected to a debate that could go in any number of directions. The last time I felt such raw excitement on the eve of a TV bout – though without being terrified that one of the contestants might passably feign normality – was in 1987 when Marvin Hagler defended his middleweight title against Sugar Ray Leonard. Their fighting styles were so wildly contrasting that the fight was virtually unscorable and almost 30 years later the result (a split decision for Leonard) remains disputed.

No doubt this debate verdict will be equally disputed in the spin room and on partisan websites, but beyond that nothing is predictable. Trump might conform to expectations by being boorish, thin-skinned and playground-bully amusing, or confound them by simulating mastery of the issues and gallantry towards a rival he claims to believe is disqualifyingly unwell.

Hillary could float above the fray on a cloud of policy waffle or sting Trump by turning it in an eye-gouging, blow-for-blow street fight to dispel concerns about her frailty. For the first time in debate history, no one beyond the two camps (and in Trump’s case, quite possibly within it) has a clue what to expect.

All we think we know is that tens of millions of Americans who are equally repulsed by both are desperately looking for a reason to support one over the other. A healthy, humorous Hillary could restore her poll lead to August’s apparent impregnability.

A sane, composed Trump speaking grammatical sentences in recognisable English might persuade the punters that he won’t necessarily incinerate the planet because the mayor of a town in Guandong province looked at him funny. Ordinarily, this would be the time to start formulating the drinking game rules (a shot for each “I love Mexicans/the poorly educated/serial killers … they’re great people!”). But ordinary has no meaning here.

The future hangs on the 90 minutes commencing, our time, at 2am on Tuesday. If it goes wrong, the only shot worth knocking back – in honour of Socrates who lent his name to high minded dialogue – will be hemlock.