Barack Obama is offering dinner with George Clooney at the actor's palatial Los Angeles home as first prize in a raffle to boost his presidential campaign coffers.

Mitt Romney had much the same idea. But the lucky winner in his raffle gets "a bite" with the presumptive Republican candidate's wife.

Ann Romney – of Welsh stock and Mormon by conversion to her husband's faith – has been assigned the challenging task of getting the voters to see beyond Mitt's stiff and sometimes testy demeanour, and to put aside the fact that as a man born to great wealth he's nothing like the average American. Her campaign is focused on women voters in particular, as support among them for Obama far outpaces Romney and has only grown with the uproar over Republican attacks on access to contraception and abortion.

But last week Ann Romney, 63, turned a widely scorned criticism of her for not having held a paid job to her advantage.

Mitt Romney has all but sewn up the Republican nomination, as Newt Gingrich last week followed Rick Santorum in dropping out of the presidential race. With the focus now on the national campaign against Obama, Ann Romney is taking on an ever more prominent role. Polls show that she is far more popular than her husband, although they also say that Michelle Obama has a more favourable rating than the woman who would replace her as First Lady.

Romney gets his wife on stage at almost every opportunity. She is the one to introduce his campaign appearances. He calls her "my sweetheart" in public and often holds her hand.

She is there in part to counter the Obama camp's attempts to portray her husband as an elitist multi-millionaire out of touch with the realities of a depression-era US who really represents only his wealthy friends. It's an easy pitch for the Democrats when Romney reveals he has paid tax on his multi-million dollar income at a rate far less then the average worker and responds to a question about whether he follows Nascar car racing by saying not really, but that he has some great friends who are team owners.

A firestorm of criticism after a Democratic pundit, Hilary Rosen, said that Ann Romney had "never worked a day in her life" because of her husband's wealth set up the Republican candidate's wife to strike back. Her first response was a tweet: "I made a choice to stay home and raise five boys. Believe me, it was hard work."

That put the Democrats on the back foot and they quickly distanced themselves from Rosen out of concern that she would be seen to be demeaning women who stay at home to raise children. Rosen was forced to apologise.

Ann Romney picked up on that theme in a speech in Connecticut, painting herself as an ordinary mom raising five boys, doing the shopping, cooking and cleaning. She knew "what it's like to finish the laundry and look in the basket five minutes later and it's full again," she said.

"I know what it's like to pull all the groceries in and see the teenagers run through and then all of the sudden all of the groceries you bought a few hours ago were gone. And I know what it's like to get up early in the morning to get them off to school, and I know what it's like to get up in the middle of the night when they're sick, and I know what it's like to struggle and to have those concerns that all mothers have," she said, to two standing ovations.

She went on to portray Mitt as a loving, understanding husband, saying he "would remind me all the time that my job was more important than his". She's also spoken about how her "extraordinary husband" stood by her side as she has lived with multiple sclerosis and battled breast cancer.

But Ann Romney gave the game away – that hers is no ordinary family with a net worth of around $220m and several houses – when she began talking about working mothers.

"My hats off to the men in this room too that are raising kids – I love that, and I love the fact that there are also women out there that don't have a choice and they must go to work and they still have to raise the kids. Thank goodness that we value those people too. And sometimes life isn't easy for any of us," she said.

She also struck the wrong note when she tried to suggest she understood the problems of financially strapped families by saying that when she and her husband were in college they had to sell some of their stocks to get by.

The Rosen controversy may ultimately have served the Democrats by once again reminding voters that a month earlier Ann Romney tried to say that her husband's incredible wealth was of no consequence.

"Look, I don't even consider myself wealthy, which is an interesting thing; it can be here today and gone tomorrow. And how I measure riches is by the friends I have and the loved ones that I have and the people that I care about in my life," she said.

In fact, Ann Romney has spent her marriage cocooned in a wealthy, white world as a dedicated member of a church with a long history of racism and misogyny.

Critics noted that she spoke about herself as if she were speaking for all women, but it only went to highlight how different her experience as a wife and mother is from those families grappling with recession, unemployment, foreclosure and insufficient funds to pay for healthcare at a time when her husband is campaigning to cut services for the poor. At other times she has struck a note of entitlement, and an "us and them" mentality.

"I believe it's Mitt's time. I believe the country needs the kind of leadership he's going to offer … So I think it's our turn now," she said in a television interview this month.

Ann Romney is not new to electioneering, although she has no love for the campaign trail. "Four years ago I said I would never do this again – was pretty emphatic about that. Because it is a stressful time and my heart goes out to anyone that participates in this event," she said this month.

She was among the most visible of the Republican presidential contenders' wives during the 2008 campaign. But she is, if anything, playing an even more prominent role this time.

It wasn't always this way. During her first campaign, when Mitt was running against Ted Kennedy for a seat in the senate in 1994, she was derided as "superficial, pampered and too deferential" to her husband, according to the New York Times. Political pundits reckoned she did him more harm than good in that election.

There's not much evidence that wives affect voting behaviour – except perhaps Gingrich's, who was a constant reminder of his infidelities and serial marriages. Ann Romney's emphasis on her 42-year marriage offers a telling contrast, even if many voters worried about such thing are doubtful that the Romneys' Mormon faith is Christian.

Mitt has long recognised Ann's political usefulness. She was the first spouse to be included in an official portrait of the governor of Massachusetts. Yet her past contains some potential red flags for more conservative voters.

Mitt is having to explain away his support as governor for compulsory health insurance, a requirement he says he vehemently opposed in Obama's reform law. The president is going to hit him on that, as well as on his previous support for abortion and gun control.

Ann Romney may come under scrutiny over a $150 donation she made to Planned Parenthood nearly two decades ago. Her husband says he will cut off all government funds to the group because among its many services to women it offers abortions.

And Ann Romney has also been left to defend a notorious incident during a family holiday long ago, when Mitt strapped their dog to the roof of the car for a 12-hour drive to Canada. She said the animal "loved it".

Ann Romney on …



Recovering from MS

"I was driven to get out of bed and get on a horse. My desire to ride was, and is, so strong that I kept getting healthier and healthier."

Her time as First Lady of Massachusetts

"It doesn't need to change your life at all. I think it's an opportunity for service and an opportunity to see people of all walks of life from across the Commonwealth."

Wealth

"I don't even consider myself wealthy, which is an interesting thing, it can be here today and gone tomorrow. And how I measure riches is by the friends I have and the loved ones that I have and the people that I care about in my life."

Criticisms she's never worked

"I made a choice to stay home and raise five boys. Believe me, it was hard work."Her husband's presidential bid

"I've never met Barack Obama, but I believe it's Mitt's time. I believe that the country needs the kind of leadership that he is going to be able to offer. And I believe he is the person that can turn around this economy. So I think it's our turn now."

Political rough and tumble

"Sometimes when I hear criticism of my husband, I want to come out of my seat and clock somebody. But you learn to take a deep breath."