Video: Obama 'Fist Bump' | Meet Mrs Obama | Michelle vs Cindy

Republicans believe that they have found a key to defeating Barack Obama by contrasting his wife Michelle, potentially America’s first black first lady, with Cindy, wife of John McCain, the Republican presidential nominee.

Michelle Obama, 44, has been portrayed as Mrs Grievance by Republican opponents, labelled a “baby mama” (single mother) of Obama’s daughters, even though she is married, and denounced for her “terrorist fist jab” - a victory punch on the knuckles - with her husband on the night he won the Democratic presidential nomination.

Rumours persist that she may have referred to white people as “whitey” on videotape with Louis Farrakhan, the antisemitic leader of the Nation of Islam, even though it is the number one item on Obama’s new rapid rebuttal website, Fight the Smears. No such tape exists, his campaign insists.

By contrast, Cindy McCain, 54, has been portrayed as a conventional adoring spouse in the mould of Nancy Reagan, whose eyes were devotedly fixed on President Ronald Reagan in the 1980s.

Cindy McCain has already attacked Michelle Obama for saying that she felt proud of her country “for the first time in my adult lifetime” during the presidential campaign. “I am proud of my country. I don’t know about you,” she said at a rally for her husband in Wisconsin, although she later admitted to feeling uncomfortable about going on the warpath.

The two families are squaring up on the battlefield. Obama has already warned Republicans to “lay off my wife” and has aggressively challenged allegations about her. The commentator responsible for the “terrorist fist” remark apologised last week but other opponents show no sign of backing off.

The Obamas are in many ways the more conventional nuclear family, if one with a modern touch. Michelle, educated at an Ivy League college, gave up her high-powered job at a Chicago hospital to support her husband’s White House bid and to make sure that their two daughters, Malia, 10, and Sasha, 7, did not feel neglected.

McCain, a prisoner of war in Vietnam, has seven children from two marriages, including two sons in the armed forces - Jimmy, 19, returned from Iraq in February - and a daughter, Meghan, 23, who has just signed a deal to write a children’s book about her father. Meghan described him as a “fantastic dad” and a “great American” last week.

Cindy McCain, who was described by one newscaster off-camera as having “weird” ice-blue eyes, is winning the popularity stakes at the moment. A poll by Rasmussen last week showed that Michelle Obama is viewed unfavourably by 42% of voters, with 25% regarding her “very unfavourably”.

Only 29% of voters have an unfavourable opinion of Cindy McCain and just 10% regard her “very unfavourably”, a gap that Republicans believe they can turn to their advantage.

The two wives have similar “favourability” rankings in the high 40s, a sign that their party bases are loyal. But independent voters are up for grabs. The same poll found that 61% of respondents said the candidates’ wives would influence their vote.

Both would-be first ladies would be more fashionable than the present incumbent. “There’s a Queen Mum quality to Laura Bush’s fashion sense,” said Danielle Crittenden, a conservative commentator and novelist.

“Cindy McCain looks very classic and very elegant and is very much in the background, whereas Michelle Obama is more edgy, modern and stylish. You don’t get arms and legs like hers without seriously working out, probably with a personal trainer.”

The fashionistas have already chosen their winner. Calvin Klein, the fashion designer, and Anna Wintour, the editor of Vogue magazine, are chairing a $1,000-a-head fundraiser, An Evening with Michelle Obama, on Tuesday at a Manhattan art gallery. For $10,000, donors can attend a private dinner with her at Klein’s home.

Camille Paglia, professor at the University of the Arts in Philadelphia, said: “I love Michelle. She’s fabulous. She has an instinct for combat and goes for the jugular. Barack Obama is much more genial. It would be a dream to have them as president and first lady.”

If party labels were reversed it is possible that Cindy McCain, who is McCain’s second wife, would be getting the harshest scrutiny. McCain, then a navy officer on a relatively poor stipend, wooed Cindy, a rodeo queen, after he returned from Vietnam to find that his wife at that time, Carol, a former beauty queen, had been disabled in a car accident.

The glamorous Cindy was an heiress whose wealth - estimated at $100m - helped to bankroll her husband’s political career. She remains an active chairman of Hensley and Co, her late father’s beer distribution company, and has released only the sketchiest tax returns under pressure.

It emerged last week that she has run up debts of between $100,000 and $250,000 on her credit card, a level of extravagance that could shock voters. During McCain’s first run for president in 2000 it was revealed that she had been addicted to painkillers and had stolen from her own charity’s medicine cabinet to feed her habit.

She could be almost as easily pilloried as Teresa Heinz Kerry, the billionaire wife of John Kerry, the 2004 Democratic presidential nominee, who was criticised as a fortune-chaser.

Instead, it is Michelle Obama’s combative style which continues to draw fire. As Maureen Dowd commented in last week’s New York Times, Michelle Obama is the newest contestant in the “sulphurous national game of Kill the Witch”.

Mike Murphy, a Republican strategist who helped to run McCain’s 2000 White House campaign, said that Michelle Obama was heading for her “big moment in the sun”. He added: “She’ll have the opportunity to do pretty well and the opportunity to really screw up.”

At the beginning of the campaign, Michelle Obama had confessed that her husband was a mere mortal with sloppy housekeeping habits who was “stinky and snorey” to cuddle with. Her frank, only half-joking criticism was emasculating, critics said, and she quickly gave up that line.

Like Cherie Blair, the wife of the former prime minister, she has continued to be a lightning rod for controversy. Friends have told her to tone down her remarks and play up her patriotism, but she has an angular style that is difficult to subdue.

“Michelle Obama is in your face,” said Crittenden. “There is a double standard operating, just as it did when Hillary Clinton was first lady. She wants to be a modern woman with her own opinions but gets criticised when she does. Cindy McCain is not getting the same criticism because she has clearly stepped back.”

Larry Johnson, a former CIA official who supported Hillary Clinton for president, believes that the “whitey” videotape controversy has not gone away despite Obama’s personal attempt to halt the rumours.

Obama said recently: “Simply because something appears in an e-mail, that should lend it no more credence than if you heard it on the corner. And you know, presumably the job of the press is to not go around and spread scurrilous rumours like this until there’s actually anything, one iota of substance or evidence that would substantiate it.”

Johnson acknowledged that he had not seen the tape personally, but insisted that it existed. According to him, it is being held back by leading Republicans “until after Denver” in late August, when the Democratic National Convention will meet to confirm Obama as the presidential nominee.

Others believe it is a tall tale, possibly based on a novel with a similar plot about a fictional black candidate for president.

David Bossie of Citizens United, a privately financed conservative attack group which is preparing a critical documentary and advertising against Obama, described Michelle Obama as “fair game” last week.

The Obamas are trying to confront rumours before they become as destructive as they were to Kerry’s campaign. The 2008 battle will be a vital test of whether fighting the smears fans the flames - or controls them.

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