What a mesmerising clip is the one of Boris Johnson making a campaign stop at a Taunton primary school but not really knowing the words to The Wheels on the Bus. I mean, how many children do you have to have had to never forget how that nursery classic goes? Wait, sorry – I forgot. Don’t answer that, prime minister.

Actually, do answer that. Can you answer that? Because – instructive as it was to learn from a Conservative video this week that Johnson prefers fish and chips to a Sunday roast – it does feel slightly as if we’re engaged in an extremely extended take on some parlour game like Just A Minute. Can the prime minister make it through an entire general election campaign without someone asking him that simple icebreaker: “And how many children do you have?”

He’s certainly managed it so far. It does help to only take press questions about once a week, and spend the rest of the time making videos in No 10, in the corridors of Conservative campaign HQ or in the back of your limo. But, you know, kids say the darnedest things, even if you only let a single pool camera capture the magic. So don’t rule out the deadliest interviewer of this campaign being a four-year-old who enlivens a Johnson visit to her nursery by randomly going: “How many children do you have?”

Two months ago, the Mail on Sunday serialised the memoir of William Cash (son of the paleosceptic Tory Bill Cash), in which this somewhat pathetic figure offered a version of his doomed efforts to bring up the secret daughter Johnson fathered with an art consultant named Helen Macintyre. If you haven’t read it, it is a deeply WTF-riven example of a particular type of upper middle class fecklessness – what Scott Fitzgerald once characterised as “their vast carelessness”. Anyway, Boris originally goes along with Cash’s plan, but it doesn’t work out. The piece ends with Cash chancing to bump into the future prime minister after some lunch speech in Davos (naturally). “Listen, it’s about Helen,” begins Cash, who inevitably feels moved to semi-apologise to Johnson for failing to help him clear up his mess. “I wanted to marry Helen and bring up your daughter as my own. It was that simple.” Johnson’s reply? “Right ... er ... got it. Thanks for letting me know.” As Cash concludes: “And then we walked off in different directions.”

Walking away is, of course, quite the speciality for Johnson, whose Wikipedia entry famously lists his progeny as “5 or 6”. Very normal. If you mention this online, people – without exception, male people – always rock up to ask why it matters. Yes, so what if the prime minister is a deadbeat who can’t face his responsibilities and leaves other people to deal with them/cover up for them/raise them? Well, I don’t know, guys?! Because it feels like it could turn out to be an important clue as to how he might handle other things? Oddly, you don’t get any mothers turning up to say: ooh, why does it matter, I’m a woman of the world here, so what if he just fucks off and shirks the day-to-day and breaks tiny hearts? And, to be super clear: you don’t get any decent fathers saying it either. Not all men. Not all prime ministers.

Facebook Twitter Pinterest Jacob Rees Mogg, aged 12. A friend who sat through his debating society contributions at school has described him as ‘like a posh Karl Pilkington’. Photograph: Bill Cross/ANL/REX/Shutterstock

The only political interview I truly want to see this campaign is one in which Johnson is submitting to questions – and a polygraph – from Jeremy Kyle. Except you don’t see men from Johnson’s background on The Jeremy Kyle Show (now axed after being accused of exploiting one of its guests to death). What is regarded as good-for-nothing and disgraceful and evidence of unforgivable moral turpitude in working-class people is regarded as winsome and excusable and even glamorously rakish in chaps like Boris Johnson. It’s why media proxies such as the MP Johnny Mercer not only took Johnson’s flak for him during the leadership campaign, but effectively thanked him for his service.

It’s the same kind of beaten deference exhibited by Andrew Bridgen MP, who couldn’t even listen to Jacob Rees-Mogg’s moronically vile comments about Grenfell last week without reflexively tugging his forelock. “But we want very clever people running the country, don’t we?” Bridgen gibbered of Rees-Mogg’s suggestion that he was too smart to have followed the fire brigade’s advice, and therefore wouldn’t have been burnt to death. “That’s a by-product of what Jacob is, and that’s why he is in a position of authority.” In fact, Jacob isn’t “very clever” at all. A friend who had to sit through Rees-Mogg’s debating society contributions at school once described him to me as “like a posh Karl Pilkington”, which now feels libellously unfair to Karl Pilkington.

Play Video 1:11 Boris Johnson struggles to say what makes him relatable to voters in BBC interview – video

Both Rees-Mogg and Johnson have been wildly overpromoted by their party on grounds of some mystical “authenticity”, yet both have been excruciatingly exposed during this campaign. All populists secretly hate their people, but most are able to fake it well enough to be adored. Johnson’s eventual visit to flood-hit Yorkshire hinted at a potential Tory misapprehension: the notion that being a selfie magnet in London seven years ago will translate nationally. As for the sensationally belated nature of this visit, one doesn’t expect the Conservative strategists to be truly altruistic, but one does bank on at least competent cynicism. If they don’t get the huge majority result they want next month, I’ll enjoy the chinstroking postmortem as to why these geniuses didn’t send the prime minister out immediately to meet flooded people IN THEIR OWN TARGET SEATS. It’s not hard, is it? Have a Cobra meeting! Look like you give a shit!

Instead, they have occupied the prime minister today with the launch of his campaign bus – long-established as his truth-delivery vehicle of choice. We know what the Johnsons on the bus do, and we know they do it all day long. We just have to wait and see if it matters.

• Marina Hyde is a Guardian columnist