Attractive female, tall, athletic, clever, GSOH. On paper, perhaps in the personal columns, Michelle Obama certainly fits the bill. Even for America’s potential first lady. The first black first lady.

Small wonder that her husband Barack’s right-wing opponents are busting a gut trying to make her appear his weakest link. Last week, Michelle was effectively forced to “reposition” herself with an appearance on The View, a daytime chat show presented by a panel of women.

It was a virtuoso performance and a necessary one. The smears against her have varied from the unsubstantiated claim that she once made a racially charged speech about “whitey”, to the suggestion that bumping knuckles with her husband was a “terrorist fist-jab”.

She hit that one out of the ball park on The View, opening the show by fist-bumping her five co-hosts, who included comedian Whoopi Goldberg and veteran news presenter Barbara Walters. “It’s my signature fist-bump,” she said, beaming. “It’s the new high-five,” she added, with an engagingly self-deprecating: “I’m not that hip. I got it from the young staff.”

It has been no cakewalk for Michelle to make the transition from well-paid, highly motivated career woman to an adjunct to her husband’s campaign, constantly in the firing line not just for what she says, but how she looks. The $900 (£460) sleeveless purple sheath dress she wore on the night Barack claimed the Democratic nomination became a topic of water-cooler chatter in every office. Not the sort of gown every working-class voter could afford but, as she emphasised on The View, hers is a classic aspirational American story.

Michelle was the second child of Frasier and Marian Robinson, a working-class family from Chicago’s South Side. Her father, who suffered from multiple sclerosis, worked as a pump operator for the city’s water company while her mother was a housewife. They lived in a rented bungalow. “We were home folks,” she says, recalling games of Monopoly and modest vacations at Duke’s Happy Holiday Resort, a Butlins-style camp in Michigan.

Her brother Craig’s prowess at basketball won him a place at an elite east coast university, Princeton. When Michelle went to visit him, she told herself: “I’m smarter than him. I can get here too.” And she did. Craig later complained to their parents that his little sister was trying to reorganise teaching methods. His mother replied: “Pretend you don’t know her.”

Princeton in the early 1980s, contemporaries recall, was still a relatively inhospitable place for minorities. Her roommate Angela Acree says they couldn’t afford furniture and just had “pillows on the floor and a stereo”. Their musical tastes were very different from those of white fellow students: “They didn’t dance.”

Michelle read sociology, writing her thesis on how blacks educated at Ivy League Princeton related to the rest of America’s black community. She wrote that the racial attitudes of some fellow students made her feel, “like a visitor on campus, as if I really don’t belong”. She felt attending Princeton would lead her into a “white cultural and social structure that will only allow me to remain on the periphery of society”. She got that wrong, but only because America has changed so much.

Such concerns did not stop her challenging her assumptions, by reading law at Harvard before joining the Chicago office of corporate law firm Sidley & Austin. She admits in her thesis to having bought into “certain conservative values”, envisaging herself in a “high-paying position in a successful corporation”.

In the summer of 1989 she was assigned as mentor to a law student getting some work experience. His name was Barack Obama. She took him to lunch to explain the firm and found herself liking him a lot. “You could laugh easily with him, so I was, like, this is a friend.” Obama wanted to be more than that and kept asking Michelle out. Initially she thought it wouldn’t “look right” as she was his professional mentor. But after a month’s persistence, she let him take her to a movie: Spike Lee’s Do the Right Thing, a story of racial conflict in a multi-ethnic New York neighbourhood.

After that he took her to one of the community self-help groups he was involved with and she began to be inspired by the Obama vision of “the world the way it is and the way it could be”.

If he got her interested in politics, she gave him a taste of the roots he lacked. Born in Hawaii to a white mother from Kansas and a Kenyan father he hardly knew, and having spent part of his childhood in Indonesia, Barack was undeniably African-American. But there was no family connection to slavery; no experience of the segregation and discrimination faced by American blacks. In his book Dreams from My Father: A Story of Race and Inheritance, Obama writes that he initially approached the race relations issue in America as an outsider.

Michelle has been a big asset campaigning in states with large black populations such as South Carolina, where her own family comes from, though she claims to make much the same speech in white states like Iowa or New Hampshire.

When Obama took her to meet some of his father’s relatives in Kenya, she observed: “There’s the view among many black Americans that Africa is home, but . . . you’re very much an American first.”

That was on her mind when she said, “I want my girls to travel the world with pride”, and when she made her remark, “For the first time in my adult lifetime, I am really proud of my country . . .” It was seized upon as demonstrating a lack of patriotism, especially by those who failed to quote her fully “. . because I think people are hungry for change.” There are, however, enough Americans who feel George W Bush has made it a lot harder to be proud of their country. That is what Obama wants to change.

It was the first lady Laura Bush who came to Michelle’s rescue, pointing out that the words of a presidential candidate’s spouse were “in many cases misconstrued”. This did not stop Cindy McCain, wife of Republican candidate John and a multi-millionaire heiress, trying to make capital out of the comment.

Michelle is not exactly a pauper. She has earned salaries of up to $275,000 even since quitting corporate law for public service, first working for Chicago’s mayor and latterly for the city’s university hospitals. Whereas Cindy McCain was a big beneficiary of Bush’s tax cuts for the wealthy, Michelle’s refrain is: “We have become a nation of struggling folks. It’s gotten worse over my lifetime and, doggone it, I’m young! Forty-four.”

She can just about claim to voters: “We’re a young couple just out of debt.” The Obamas had large student loans, only repaid by the sales of Barack’s two books.

Her informal language – “Doggone” and “Jeez” – emphasises that she is a relatively normal “working soccer mom”, whose chief concern is her family. When their daughters Malia, 9, and Sasha, 7, were given a giant cookie shaped like the Obama logo, she complained: “More sugar for the kids.”

She worries about junk food and high-fructose corn syrup in fruit drinks. Friends say she keeps herself in trim by exercising “like a gladiator”. She admits to a tricky patch in their 16-year marriage when Barack was working so hard she barely saw him, but puts it down to her stable upbringing being different from his.

Although he has worked in Washington since election to the US Senate in 2004, she stayed in Chicago to give the girls stability and insisted he got home Thursday to Sunday. When at home, he makes the beds and does laundry, “because the girls need to see him doing that”. She describes him as a “fabulous husband and father” but has not shied away from airing his dirty laundry in public, almost literally: describing how he leaves socks lying around. We have been told the potential next US president can be “snorey and stinky” in the morning, which even in a campaign that boasts of its transparency may be too much information.

In his book The Audacity of Hope, Barack noted a rarely seen vulnerability in his wife: “The slightest hint of uncertainty, as if, deep inside, she knew how fragile things really were, and that if she ever let go, even for a moment, all her plans might quickly unravel.” Over the coming months, that will be tested as never before.

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