The First Lady of fashion

"There's nothing wrong with wanting to look pretty," Mrs Obama has said and she has taken her advice literally with a string of well-cut shift dresses for key events, the most outstanding being Carla Bruni-esque deep lilac with an Alaia belt and a bright turquoise version from her favourite Chicago-based designer Maria Pinto.

There is an obvious reverence for the tradition of Mrs Kennedy here, in neat fitted jackets worn over luminous figure-hugging dresses: but without the attendant sense of super-high spending.

So where Jackie O favoured real pearls, Michelle pays credit-crunch homage, wearing huge fake ones, which have duly become a trend.

After she was briefly outshone by Sarah Palin, whose $150,000 wardrobe looked good but cost her dear in terms of her claim to represent "ordinary" America, all eyes are now back on the woman most likely to move her wardrobe into the White House.

Not for her the Hillary Clinton hyper-groomed look of the sisterhood of the travelling pants suit - she is rarely seen in trousers, other than wide Calvin Klein palazzo pants for evening wear, with a tunic by Isabel Toledo. That brought a chorus of approval from US fashion editors who admired her judicious eye for a less well-known designer.

There is politics at play, too. Ms Toledo is a proud Latina and Mr O needs ethnic minority votes beyond the black community.

Fashion has already cast its vote. Mrs Palin's heroic attempts notwithstanding, Anna Wintour gave a fundraiser for the Obama campaign last week attended by big name designers, and Diane Von Furstenberg is a vocal supporter of the Obamas.

Mrs Obama's is a prosperous working-women's style, a mile away from the cautious Ralph Lauren uniform of Laura Bush or Mrs Clinton's forays into technicolour mustard and royal blue. You might actually want to wear something that Michelle owns.

However, she's unlikely to mince around so fetchingly in tight jeans as Mrs Bruni. Asked if she would go clubbing with her French equivalent, she replied recently, a touch curtly, that she went to bed far too early for such trivia.

Her trademark bob is on the messy side of neat, as worn by Kate Moss, Gwyneth Paltrow and the new Bond girl Olga Kurylenko. Now the old rigid TV anchorwoman blow dry, with enough root lift to launch a Nasa programme, is out, out, out and Mrs O is very definitely in.

Just don't expect her to lift the sales of Jimmy Choos: at 5ft 11in, she only wears flats. No one is allowed to be taller than the President, not even in the name of style.