It was, for us legion of Sarah Palin obsessives, a disappointing debate all said. No moose-in-night-sights Couric interview dead air, no dizzying glimpses down the bottomless well of her unknowledge, no dinosaurs, no pipelines mandated by God. No foxy peep-toe heels, jewel-bright jackets or Christmas-cracker ear-wear - funereal garb now a universal political signifier of earnestness in hard times - and no definitive answer either to the most pressing issue of the campaign so far: did Sarah Palin, as the Huffington Post claims, have her lip-liner permanently tattooed on?

Instead, we had Mrs Palin in Pygmalion, marshalling her notes, getting those harsh, flat snowline vowels around foreign leaders' names learnt by rote: enunciating Hamid Karzai and Kim Jong Il not once but twice, because now - listen up, you snippy media folks! - she darn well can. Professor Henry Higgins-Kissinger has schooled her well, as have the strategist crammers who locked her away in John McCain's Arizona ranch, not letting her take the bunch of marbles from her mouth until she could say Mahmoud Ahmadinejad.

But then Mrs Palin didn't need to be much more than a Pygmalion politician: to show she is a fast study, able to muster an appearance of competence and fluency, to leave the Saturday Night Live team scratching their heads for easy one-liners.

Eliza Doolittle didn't win hearts for her newly acquired grasp of polite manners, but because of the hot, unschooled heart that oftentimes beat through her shell of shallow learning. And the joy of Mrs Palin, what endears her to Middle America and fascinates every British woman I know, is her quality that cannot be bottled and sold: authenticity.

It shines out, even through her shopping-channel presentation, the Day-Glo patriotism of her XXL Old Glory lapel pin, her talent for talking while perpetually smiling (which, ask Gordon Brown, is a tough trick to pull off without looking deranged), the cheeseball winks, the local DJ shout-outs to kids at her brother's elementary school, the exaggerated nose wrinkles when uttering something as disgusting as “single-sex relationships” or “redistribution of wealth”. She is Nicole Kidman as the driven weather girl in To Die For, Reese Witherspoon, the ruthless high-school candidate in Election. A candy-coated ball of granite.

When she offered “a bit of reality from Wasilla Main Street”, Joe Biden had to counter quickly with the word down in Kay's Restaurant and the Home's Depot in Wilmington. When Mrs Palin played her son in Iraq, her special-needs baby, her worries about college fees, Mr Biden had to match it with a soldier boy of his own and raise her with his dead wife and daughter, then an emotionally welling remembrance of struggling to raise two injured sons alone.

And you could detect frustration and pique in Mr Biden's lament that, “just because I'm a man”, he doesn't understand the hard decisions made over that mythical American kitchen table. But perhaps in this alone women politicians have an advantage, being the ones most able to convince voters that they have seen the inside of a maternity ward, a supermarket, a classroom, have dried tears and chewed pencils over household budgets.

I wonder why our own women politicians never use the power of their experience this way? Even Diana, a privileged princess, understood how motherhood is a universal connector, giving you common cause with women from Lambeth to Lesotho. David Miliband may pose at home for The Times with his monstrous glacier-melting fridge, but I can't recall the Harmans, Kellys or Smiths ever opening up their domestic lives this way. Perhaps, as with female bankers taught never to display children's photos on their desks, British women politicians strive to draw attention away from, not towards, their gender. Or maybe they fear that heartfelt maternal tales will sound limp and milky. But the power of Palin - what I enjoy about her, despite myself - is that she celebrates mothers as tough and capable, resourceful and stoic: moms as the political front line!

In boom times a politician can appear to be Everyman, with a tea mug emblazoned with a photo of his first-born. In hard times he must convince us that he feels - or at least hears - our pain. Which is why the Tory tanks, seemingly unstoppable in their squishing of new Labour, have for the moment stalled.

While the good times rolled, we could safely indulge the posh boys: feeling flush, we even felt we might aspire to their lives, or at least to drink in the same bars and buy copies of handbags carried by their wives. But now the line is re-emerging between them and us, between those cancelling their skiing holidays and those losing their homes.

Perhaps David Cameron - Biden-style - could start speaking of the economic hardship he has heard about while queueing for organic squash in Tom Conran's Deli, Notting Hill, or recount the travails of fellow parents at St Mary Abbots, Kensington, these days the whitest, wealthiest state primary in all of Christendom. Or maybe the cold and patrician George Osborne, with his even chillier wife making her pile writing remembrances of her über-grand great-grannies, should pretend that their hedge-fund friends are all juggling maxed-out cards.

Authenticity is now at a premium. William Hague, with his soft Yorkshire tones, his tales of delivering fizzy pop to streets like my own, is an asset at this hour. Perhaps he is dragging out his kitchen-table conservatism even now. Even John Prescott, oddly, is a voice for these times, as is Alan Johnson, who raised three kids on a council estate. Peter Mandelson, with his slick suits and slippery mortgage, is the last face voters can bear. But then Gordon Brown has the more clearcut task of steering the ship between the icebergs: Cameron must get with the bodies in the water.

After that debate, those who loathe Mrs Palin will still loathe her; those who cleave to her will find no new reason to be repelled. It is just shtick, she's sticking to the rigid train tracks of her notes, you tell yourself when she says how Saturday soccer parents fret at the touchline over their investments. But then the debate ends, her great messy family spreads out on stage, and Mrs Palin tenderly passes her always-placid Down's baby to her little girl. The sound is off, the scripted babble is over. It is a silent gesture, something compellingly real in a cooked-up world.

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