After his death in 1989 at the age of 88, Democratic senator Claude Pepper was remembered, with characteristic American restraint and understatement, as “the nation’s foremost champion of the elderly”. On the subject of his own ageing, though, the one-time lawyer appeared to experience a short-lived existential crisis featuring an ill-advised toupee before settling on the path of mordant acceptance. “A stockbroker urged me to buy a stock that would triple its value every year,” he once observed. “I told him, ‘At my age, I don’t even buy green bananas’.”

Pepper has been dead for 35 years, but for voters contemplating another MAGA election (Make America Geriatric Again), his work to advance the rights of the elderly has been buried under an avalanche of fillers, fake tan and frequent faux pas. For the two main contenders, it should be a zero-sum game. At 81, President Joe Biden is just 3½ years older than Donald Trump, who turned 78 on Friday.

Instead, though, watching the pair spar with one another is like seeing a couple of demented long-term neighbours who, having settled in for the duration, nonetheless continue to duke it out by exchanging insults and periodically tipping the fetid contents of their bins over one another’s prized petunias.

The problem is, in this case, the petunias in question are the American people and, by extension, anyone with a vested interest in ensuring that whoever wins the race to the retirement home, nay, White House, is someone who has the physical stamina for the job (regardless of age) and, critically, is still fully compos mentis.

What makes the situation even more farcical is the efforts of both candidate’s campaign teams to camouflage their frequent verbal (and sometimes physical) slip-ups using the dark arts of clarification, expurgation and obfuscation.

Biden and Trump, meanwhile, spend much of their time in wedding-guest mode, pinballing between leading the chicken dance (albeit against the orthopaedic surgeon’s instructions) and emitting what one political commentator last week described as Trump’s “drunken uncle vibe”.

The effect is bewildering, and the outcomes astonishing. For his part, Trump has regularly sought to prove his mental acuity by brandishing a note that his doctor could not possibly have been strong-armed into writing while reassuring supporters that he “aced” the last cognitive exam he had taken. “I’ll let you know when I go bad; I really think I’ll be able to tell you,” he said.

It might already be too late. In recent months, Trump has mixed up the leaders of Hungary and Turkey, praised fictional serial killer Hannibal Lecter as a “wonderful man”, and warned that the world was facing a second – instead of third – world war.