In 1992, a year before her husband became president of the United States, Hillary Clinton accompanied him to a TV interview in which he was quizzed about his alleged affair with Gennifer Flowers. Hillary wore a demure turquoise suit and a black Alice band to hold back her long blonde hair. Then she spoke: "You know, I'm not sitting here like some little woman standing by my man like Tammy Wynette. I'm sitting here because I love him." She spoke without even the slightest insinuation of a smile.
Hillary appeared to be the ultimate political wife - forced, contrary to her defiant statement, to stand humiliated by her man as the world picked over his "relations" with a string of women. But then she embarked on her own political career. Take that, Tammy!
Perhaps Wynette, if she were still alive, would find more to sing about in Britain. As the leaders' wives are pushed on to the election stage - stepping through the red curtain in their decoratively unobtrusive outfits - you can hear her bawl: "Stand by your man, and show the world you love him."
All this showing. It's why we get "My husband, my hero", courtesy of Sarah Brown. Or, from Samantha Cameron: "So much of the Dave that I first met and fell in love with is Dave the politician." Apart from inflicting a small but persistent wave of nausea on the casual listener, these statements are Wynette enacted, spoken to show the world the full glory of their wifely devotion (note, however, the exception of Miriam González Durántez, wife of Nick Clegg, who deserves a cheer for her response to the label of political wife: "I dislike that name . . . I don't have a role, I'm just married to him."
Sarah Brown and Samantha Cameron are intelligent and successful, but for some reason they feel obliged, in the face of a moralising press and a hungry public, to toe a stultifying line. We are loyal wives, they say, proud of our brave husbands. I love him, so you should, too. And the best way of expressing your love, in case you weren't sure, is through the romantic gesture of a vote.
Although the tender affirmations of affection are squirm-inducing, they are more tolerable than the other trick - the one where the spouses disclose the details of their husbands' naughty habits. These "family life admissions" (or FLAs - as in, Andy Coulson: "Dave, the polls are down again. Can you get Sam to do a couple of FLAs over the weekend to give us a boost?") give us Dave the channel-flicker and BlackBerry-fiddler, "not good at picking up his clothes". As for Gordon, he's messy, noisy and up in the morning "at a terrible hour". They assume a thought process: "Oh look, Gordon Brown is messy. So's my husband. I'll vote for that one, then."
In their portraits of their wayward husbands, Sarah and Samantha morph from doe-eyed idol-worshippers into doughty matrons, ticking off their charges as they crash through the house with their toys and their politics. The wives are the strong ones, binding the family together as the husband saves the world, leaving the inevitable but charming dirty socks in his wake. Strategists in campaign headquarters imagine women across the land (particularly in key marginals) shaking their heads in benevolent recognition and sighing, "Ah, men!"
Oh, spare us all this, can't you? Admittedly there's no escape from media obsession for modern political wives: they make for a better picture than their husbands (how many times can you do an outfit analysis of a suit?). But it seems they're only too willing to feed the monster: the strategic appearances at appropriate fashion shows, the gentle statements of support. Some say it's patronising - a calculated way of appealing to a female voter who is supposedly more interested in shoes than the deficit. Others suggest that it's yet another example of the Americanisation of our politics - hung up on personality and image.
But I'm not sure about this high-minded disapproval. My problem is that it all seems so studied, so dull. It almost makes me miss Cherie Blair with her nightie and poor choice in property advisers. But it's thanks to Cherie, and her outspokenness, that the new tone was set for the modern leader's wife. She wrote the guidebook: How to Make a Prime Minister's Life More Difficult Than It Needs to Be. Having studied it, and burned it, the wives are now carefully hemmed in, speaking only when adulatory and avoiding what Sandra Howard called "the minefield".
That is, until 22 March, or Magic Monday, as it may from now on be known: the day that Samantha Cameron's saucy attic photos popped up in the Daily Mail and she revealed she was pregnant. The pictures, styled by the fashion writer Alison Jane Reid in 1997 or 1998 (she couldn't remember which), would "leave the Tory old guard spluttering", said the Mail. They show Samantha in her late twenties, cavorting with kittens and posing seductively in a small white dress. It's all a bit of a wince and probably not quite what Coulson had in mind for his secret weapon.
Despite the cringeing, or because of it, the photo affair was oddly refreshing. For a few hours, before the beautifully orchestrated announcement of the Cameron pregnancy, there was some respite from the honed appearances, the controlled stage management. The pictures will disappear in the wake of the baby news, but for that brief moment, with their republication, the rulebook was set aside. (On the baby: is it cynical and absurd to entertain the idea that it was conceived, in all senses, as an election strategy? Yes. But.) Now all we need is for Sarah Brown to come out of the closet as a former motorcycling Goth or the lead singer in a punk band. Wishful thinking, I suspect.