Will Michelle be the radical in the Oval Office?

Instead, she has emerged as the campaign's strength, dubbing herself the "mom in chief", and focusing in interviews on family life while radiating pride in her husband.

Fears ran high that Mrs Obama would be cast as a black Cherie Blair or Hillary Clinton — casting doubts on her husband's moderation, and making his campaign what it least wanted to be: one defined along mainly racial lines.

Her background is less racially mixed than her husband and she has devoted more of her time to all-black issues: her student dissertation at Princeton was about the often fraught relationship between black graduates and their home communities. She grew up on the south side of Chicago in a working class family which prided itself on pushing its children to excel — her brother also attended Princeton, on a sports scholarship.

Deeply rooted in Chicago's black churches, she brought the young Mr Obama to her circle when they started dating: one of their early outings after seeing Spike Lee's Do The Right Thing and dinner was to a Sunday service.

She introduced Mr Obama to the Reverend Jeremiah Wright, who became a close friend. His "God damn America" outpourings provided the campaign's riskiest moment. Combined with her comments that she was most proud of her country when her husband became a presidential candidate created a danger zone.

But as David Axelrod, Mr Obama's campaign manager, says: "She's smart, she didn't need to be told" that she needed to watch her phrasing after that.

The decision to allow Michelle to introduce her husband at the Denver convention was considered risky inside her husband's team. Strategists finally agreed that the American public would feel easier about envisaging Mr Obama in the White House if it felt more familiar with his wife.

At 5ft 11in, Mrs Obama is only slightly shorter than her husband, so it was decreed that she would stick to flat shoes in public appearances.
She duly dazzled in her trademark jewel-coloured shifts and her performance was deemed one of the high points of the campaign, reinforcing her husband's lead with women.

What we have witnessed has been a Michelle Lite, combining her fondness for original designers in New York and Chicago with the claim to shop at the Target budget store for lavatory roll.
In truth, we do not know what influence the real Mrs Obama will wield on Pennsylvania Avenue, because her real passions and concerns have been so carefully enfolded in a welcoming and inclusive image.