I have worked in advertising for 28 years. In that time I have seen many briefs for communication campaigns, but none contained the line ‘It is important to insult the target audience, or at least treat them with barely disguised disdain.’

So I wonder whether the referendum result might have gone the other way had Remain supporters refrained from using social media in the days before the vote. Impossible to enforce, of course. The problem with the self-righteous is that they are so eager to virtue-signal to each other that they will go on doing it even when it is completely counterproductive. One American expert has written a blog post entitled ‘Liberals, Want Trump to Win? Keep Calling Him Racist.’

Progressive people are always more inclined to disparage conservatives than vice versa. One explanation, as Jonathan Haidt explains, is that the moral intuition of conservatives is, perhaps surprisingly, more complex than that of liberals. Hence conservatives often see liberals as benign but naive; liberals, however, who find many conservative concerns incomprehensible, think conservatives are evil or mad. Fair enough. But suggesting that anyone who disagrees with you must be either racist or uneducated is never an effective way to change someone’s mind. ‘You are an arsehole and here’s why’ is possibly the least persuasive sentence there is.

Faced with such abuse, most normal people say nothing. This makes the problem worse, because the remaining people who do speak up usually are extremists. It’s the same selection bias you get with demonstrations: normal conservatives don’t go on marches (the only use we have found for handheld placards is to advertise golf sales), so when TV crews do report a rare right-wing demonstration it is disproportionately formed of the kind of people who name their children after Norse gods or own a suspiciously large collection of decommissioned military vehicles.

But if disdain and educational snobbery (the metropolitan left’s one allowed prejudice) aren’t generally very good tools for winning over people’s hearts, there is another way which is even worse. Try threats. The Remain campaign was so tin-eared that it failed to notice when Project Fear mutated into Project Threat. Project Fear wasn’t a bad idea in principle. But people respond very differently to blackmail. The Remain campaign’s central message reminded me of being arrested in the Middle East, when I was repeatedly told ‘If you do not make this easy, things will not go well for you.’

The Obama intervention was a disaster. Enthusiastic Remainers probably became mildly tumescent in his presence; everyone else found his single memorable phrase ‘back of the queue’ creepily intimidating. Someone from a country which wouldn’t even pay us a small tax on tea, and which has trade deals with the very countries which fund Isis and al--Qaeda, now tells us to wait behind Paraguay? And that was before Osborne’s threat of a post-Brexit Budget, and menacing comments by Jean-Claude Juncker, someone who would easily make it to the semi-finals in a World’s Most Odious Man competition.

But let’s not forget that the referendum itself was also an act of intimidation. Experts in behavioural science were engaged to perfect the wording — hence ‘Leave’ and ‘Remain’ rather than ‘Yes’ and ‘No’. But no one questioned the choice architecture itself. Framing a complex question as though there were only two possible answers (cf. Scottish independence) was a monstrous and polarising act of brinkmanship — of playing a game of chicken with the electorate. At some point it was inevitable they’d stare you out.

The Remain campaign failed to notice when Project Fear turned into Project Threat

Rory Sutherland is vice-chairman of Ogilvy Group UK.