Over the past five months Michelle Obama has basked in some of the most flattering reviews ever earned by an American first lady. Yet the first stirrings of discontent are beginning to surface as President Barack Obama’s wife emerges from her newly installed White House vegetable garden in search of a meatier political role.

Reports last week that she is seeking to expand her influence in her husband’s administration set alarm bells ringing among Democratic veterans.

Despite denials from White House officials that Michelle Obama is suffering from “Hillary-itis” — a burning desire to help her husband run the country — her long-running interest in healthcare has raised painful memories of 1994, when Hillary Clinton presided over a political debacle as her health reform proposals collapsed in Congress.

As a Harvard-educated lawyer and a former hospital administrator from Chicago, Michelle Obama has been dealing with the shortcomings of US healthcare for much of the past decade.

Yet since her husband became president in January she has mostly steered clear of the contentious debate over the soaring costs of treatment, insurance and care for the poor.

Instead she has emerged as a fashion icon, a model mother and a symbol of African-American achievement. The angry black woman who once suggested she had not been proud of her country until her husband ran for president has since been hailed as the most glamorous first lady since Jackie Kennedy.

To the astonishment of Republicans, who regarded her as a potential liability to her husband’s campaign last year, her approval ratings have consistently outstripped her husband’s.

Yet Democratic insiders have long suspected that Michelle Obama was ill-equipped for a background role as a dutiful spouse. “You know when she was happiest during the election?” asked one party strategist. “When Barack had to go back to Hawaii for his dying mother and Michelle took over his campaign.”

Earlier this month she caused a minor stir in party circles when she abruptly replaced her White House chief of staff after only four months in the job.

Jackie Norris, 37, had been Barack Obama’s campaign co-ordinator in the early primary state of Iowa and had apparently hit it off with his wife. But Norris later fell out with Desiree Rogers, a Chicago businesswoman and close friend to Obama who had become the White House social secretary.

When Norris was quietly shipped off to a different job, Michelle Obama turned to Susan Sher, 61, another old friend and her former boss at the University of Chicago Medical Center.

Sher told The Washington Post last week that her first move as Michelle’s new chief of staff was to tell David Axelrod, the president’s senior adviser, that he needed to return her calls immediately.

Since Sher took over, Michelle Obama has become perceptibly more vocal about healthcare and community issues. Last week she visited San Francisco to launch a summer volunteer programme.

She also sent an e-mail to millions of Democratic supporters urging them to support her husband’s healthcare proposals, then gave a television interview to discuss her role in fighting childhood obesity.

Urging Americans to embrace a healthier lifestyle, she added: “Government can’t do it all . . . my hope is that if I play a role in sort of ringing the bell of prevention and wellness and exercise . . . I think that can be helpful.”

Acutely conscious of the Clinton precedent — which not only scarred Hillary’s reputation but also set back the cause of healthcare reform for a decade — White House officials insist the president’s wife will steer clear of policy controversy.

“It has never been our interest in having the first lady play a prominent or leading role in advancing our policy positions,” said one official. “You are not going to see her out there on the stump.”

Oprah Winfrey recently described Michelle as “an authentically empowered real woman who looks and feels like a modern woman in the 21st century”. Others have praised her as a symbol of middle-class, feminist accomplishment and stylish working motherhood.

Michelle Obama gave up her $300,000 (£182,000) a year job to be a stay-at-home president’s wife. To expect a woman of such substance to bite her tongue on controversial issues may prove unrealistic. She has already instructed her staff to think “strategically” about maximising her impact on the issues she addresses; she is also hiring her own speechwriter.

Sher insisted Michelle Obama was not about to turn into Hillary Mark Two: “My own perception of it is that she doesn’t want to get involved in . . . wonky policy issues \ the kind of contentious legislative proposals that are going on at any given time.”

Other Democrats are beginning to wonder how long she can restrict herself to such uncontroversial subjects as her daughters’ enthusiasm for vegetables.

“Sasha likes peas,” she said last week. “And Malia is a pretty big broccoli fan.”

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