Donald Trump pointing and talking into microphone.

Tonight’s presidential debate marks a series of firsts. No debate has taken place this early, most are in the autumn just before the elections in November. None has occurred before the candidates are ratified by their party conventions, no previous debate has involved a sitting president and a previous incumbent, none has involved such unpopular candidates, and no previous contest has focused more on the men themselves rather than the issues. For most people watching the contest is less about who is best on the policy issues and more about who is the least senile and most mentally fit for office.

The fact that so much attention has been spent on the format of tonight’s debate is indicative of the high stakes and peculiar nature of the contest. Trump’s team insisted that the candidates be seen walking to the stage hoping to demonstrate Biden’s ageing gate. His team also demanded that they both stand for the full 90 minutes as a test of stamina. For Biden’s team, there was an insistence that there be no heckling audience and no bullying rhetoric from the other podium. Microphones will accordingly be cut after two minutes to prevent the contest from descending into the haranguing match that characterised Trump's debates in 2016 with Hilary Clinton and the previous match-up with Biden four years ago.

The focus on format is indicative of the fact that each side recognises the vulnerabilities of each side and that the policy discussion matters less than the need to avoid a fumble, either physical or verbal. In 1992 President George H.W. Bush looked at his watch part way through the debate, an action that was spun to show that he was contemptuous of the process and would rather be somewhere else. He went on to lose to Bill Clinton. In 1976 President Gerald Ford made the extraordinary statement that “There is no Soviet domination of Eastern Europe” and in a moment lost the support of the Polish-American community in the Midwest going on to lose to Jimmy Carter. In tonight’s debate avoiding such gaffes is even more important than ever. In an age of cut and posted clips and reposted memes both sides will be focusing on exchanging rehearsed one-liners that they hope go viral and hoping that the most viewed clip of the evening is the killer gaffe made by their opponent.