If John McCain had hopes of an upset when Michelle Obama took over her absent husband’s presidential campaign last Friday, they dissolved in the cascades of adulation that swamped the Democratic candidate’s wife as she stormed triumphantly across Ohio.

Barack Obama’s decision to quit the campaign trail to visit his ailing grandmother in Hawaii had injected a sudden note of uncertainty into what opinion polls are beginning to portray as his unstoppable procession towards the White House.

It also presented his wife with a potentially awkward challenge – to avoid any repetition of the damaging controversies that marred her first forays into the campaign earlier this year. Republican strategists seized on a series of remarks by Michelle to portray her as an angry radical with a low opinion of her fellow Americans.

Over the past few months, to the consternation of frustrated Republicans who believe she has been spared proper scrutiny by a fawning media, Michelle has quietly been repairing her combative image.

Confidently stepping into the national spotlight in Columbus and Akron on Friday, she declared: “I come here as a wife.” She referred to her husband as “babe” and “my honey”, and reassured audiences that his grandmother, Madelyn Dunham, who will be 86 today, was “doing fine”. She also talked about her daughters’ preparations for Halloween, when Sasha, 7, and Malia, 10, will be dressed as a “corpse bride” and an “evil fairy” respectively.

Of the outspoken black radical who once talked of America being “just downright mean”, there was no trace. She had written in her university thesis that “I will always be black first and a student second”; she complained often during the Democratic primary campaign that America was being “guided by fear”.

Yet in the swing states of Ohio and Florida last week, she stressed positive American family virtues such as hard work, generosity and decency. She portrayed herself not as a political animal, but as a mother devoted to her children. “When people ask me how I’m doing, I say I’m only doing as good as my most sad child,” she told a packed school gymnasium in Akron.

So which is the real Michelle Obama? The opinionated political wife whose husband once said of her, “She can be a little meaner than I am”? Or the safe, smiling spouse who in two Ohio meetings was so busy singing her husband’s praises that she never once mentioned the names of his Republican rivals, John McCain or Sarah Palin?

Michelle’s cosy transition from potential campaign liability to saccharine schmoozer-in-chief is frustrating Republican activists who complain that a biased media has eased off on the Obamas while increasing sexist attacks on Palin, the first female governor of Alaska, and Cindy McCain, wife of the Arizona senator.

“Can you imagine Saturday Night Live [a popular satirical programme] doing weekly send-ups of Michelle Obama using a black comedienne to mimic and mock her voice and accent?” asked Patrick Buchanan, a prominent right-wing commentator.

Buchanan noted that when The New Yorker published a cartoon of Michelle in a black liberation-style afro wig with an AK-47 rifle slung over her shoulder, its editors faced an avalanche of criticism. They had to scramble to explain that they weren’t mocking Michelle, but were attempting to ridicule the critics who portrayed her as a kind of terrorist.

Yet Palin is routinely portrayed by Saturday Night Live and many others as a moose-hunting idiot from a white trash family that spends most of its time having sex before marriage or smoking cannabis. Several recent profiles of Cindy McCain have focused on her past addiction to prescription drugs and her family’s inherited wealth. “Is there a media double standard?” asked Buchanan. “You betcha.”

Republican concern about Michelle’s likely role as first lady is partly based on what one party strategist last week described as “the Hillary precedent”. After years of Republicans portraying Hillary Clinton as a dangerous feminist subversive, the strategist added: “I’ve got a feeling we’re going to look back on Hillary as a saint, compared to what we’re in for with Michelle.”

Yet her performance at the end of last week was a masterpiece of bland reassurance. Speaking to friendly, mostly African-American audiences, she hailed her husband for deciding to tackle “the tough streets on the south side of Chicago”, instead of taking a well-paid job on Wall Street.

That experience of poverty, struggle and decay meant that “Barack Obama gets it,” she said. “He worked in neighbourhoods where jobs disappear and opportunities are just gone for years – don’t we deserve a president with that kind of experience?”

Of serious policy issues there was little discussion, but few in the Ohio crowds were worried. The meetings had the air of an old-style evangelical revival, except that instead of pledging to follow the Lord, the faithful had come to worship the Obamas.

“You really are fired up,” Michelle noted admiringly after one prolonged burst of shrieking. “Oh, she’s so beautiful,” sighed Ruth-Ann Joseph, a Columbus teacher who wore a “Women for Obama” sticker across her cleavage.

On the other side of the state, Palin was provoking similar scenes of rapture among local Republicans last week, but the latest polls put Obama ahead in Ohio by an average of seven points.

Republican groups are resorting to desperate measures to try to scare away Obama’s support. The right-wing National Rifle Association is running a radio advertisement in Ohio that warns gun-owners of “predators breaking into your children’s bedroom – but Obama won’t let you shoot them”.

Yet not every indicator favours the Obamas. Michelle’s recipe for shortbread biscuits was recently beaten into second place in a closely watched national cookie contest that has correctly predicted the result of the past four presidential elections.

The winner of the Family Circle magazine presidential bake-off was a recipe for oatmeal butterscotch biscuits submitted by Cindy McCain.

Additional reporting: Christine Finn in Honolulu

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