MY Higher English teacher worked to the theory that if you named someone, you owned them.You had power over them, he said, you understood them.

He mainly exercised his thesis on the more problematically behaved members of the class, among whom I was too lacking in imagination to be numbered.

He called his wife The Haystack. I’m not sure what that conveyed, other than that she was blonde and quite tall and slightly triangular of build.

Politicians similarly subscribe to this theory. Theresa May has been talking about Jam families, as if we should know what she’s talking about. As if, indeed, she knows what she’s talking about.

I thought, when I first heard it mentioned, that this meant families who were being spread thinly. Why not Marmite families (binary voters)? Or Primula families (cheesed off voters)?

Ah, but it’s Just About Managing. A clever acronym, see?

Mrs May is far from the first politician to rely on on a snappy soundbite or acronym to satisfy the inclination to categorise the populace. The Chancellor, Philip Hammond, is similarly nuts about Jams.

The Mondeo Man was the voter Tony Blair wanted to hook in order to win the 1997 election. Worcester Woman was targeted in the 1997 and 2001 general elections.

Don’t forget the “hard-working families”often patronisingly talked about by George Osborne and David Cameron, or ex-Labour leader Ed Miliband preference for the term “squeezed middle”.

White-van Conservatism - aspirational working-class voters - nearly did for Labour’s Emily Thornberry, who stood down from the shadow cabinet after a snobbish tweet about White Van Men.

Ms Thornberry was, you see, viewed as demonstrating her allegiance with the the London left, the so-called metropolitan elite, and, worse, Champagne socialism.

And who can forget the abject failure of Nick Clegg’s Alarm Clock Britain? “Now more than ever,” he wrote. “Politicians have to be clear who they are standing up for.”

Clegg was standing up for anyone who needed a device, other than their own Circadian rhythm, to wake them in the morning.

There’s the problem with these gormless monikers: they’re completely meaningless.

For the squeezed in the middle Jam voters, the previous Tory administration concentrated on the lower middle classes, but Mrs May has widened her focus to include the upper working classes. The definition cannot be too narrow or it will exclude certain groups; too wide and it falls between two stools.

Political descriptors are an abuse of cliche, a patronising turn-off, suggesting politicians have no clear idea of who they represent. And who’s surprised? After all, this is a government turning tired idiom into political strategy: whose Brexit negotiation aims, according to a handwritten note photographed in hands of Tory aide on Downing Street, are: “Have cake and eat it.”

Naming is about control, not empathy. Labelling only serves to demonstrate how distant political parties are from voters. It shows they rely on focus groups more than real life. And when you unwittingly demonstrate how distant and out of touch you are with voters, you end up with the likes of UKIP and Trump sidling in to the gap in understanding.

It is the crisis of confidence of politicians, to use a cliche, in a nutshell.