Among her copious missed chances to capitalise on her opponent’s weaknesses in St Louis, though, one omission stands out.

Around halfway through, Trump and Clinton both dithered over who first should answer a tricky question on healthcare. “I'm a gentleman, Hillary," Trump insisted. “Go on.”

The chutzpah was astonishing: 24 hours earlier, a now-infamous video had leaked in which this man had bragged about sexual assault. A quicker debater than Hillary would have seized on it.

Instead, she hovered, let the audience laugh gingerly, and started talking about insurance premiums. Then, this week, Trump’s wife Melania sat down for a US TV interview in which she insisted “my husband is a gentleman” to a visibly awkward Anderson Cooper.