Meet Mrs Bush's rivals for the title of First Lady of the US - some of whom have already been making waves.
By Kathryn Westcott
BBC News Online
The Kerrys: A candidate's wife is expected to provide the human touch
Journalists love Democratic front-runner John Kerry's wife Teresa. The flamboyant, multi-million dollar heiress of the Heinz food empire has delighted commentators but rattled the nerves of campaign managers.
"Outspoken" is a word that is most commonly used to describe the 65-year-old.
She has spoken candidly about using Botox, prenuptial agreements, and said she would "maim" any husband who was unfaithful, adding jokingly that she "might be into 18-year-olds".
In November, she described the Democratic debates as a silly waste of time.
But Teresa, along with the other First Lady nominees, can only expect the attention to intensify as campaigning heats up.
"The First Lady provides a context into how you evaluate the president," Lewis Gould, who is currently editing a series of books on modern First Ladies, told BBC News Online.
"The spotlight begins to apply itself to every detail of the potential presidential family, so issues of how the children are raised, what the potential first lady does, the background and heritage all come into play."
Emphasis on marriage
All the Democrat wives, with the exception of Howard Dean's spouse Dr Judith Steinberg, have spent a significant amount of time on the campaign trail. They are playing the ultimate supporting role in a presidential campaign well, by letting voters know that they are standing behind their man.
But if Mrs Heinz Kerry's outspokenness has proved controversial, keeping quiet can be equally testing.
Dr Steinberg has incurred the wrath of many for shunning the campaign trail. Her preference for concentrating on her work as a GP has been criticised for defying tradition.
Many people see her as a role model for independent women who balance careers and children, while feminists applaud her refusal to be reduced to an adjunct of her husband.
But, most commentators conclude that her absence could be a possible liability to her husband's chances.
Gert Clark has played a more traditional role of political spouse
"Americans want First Ladies to have an independent life, be their own person but at the same time, they want them to defer to the idea that presidential elections are the most important thing that we do as a nation every four years. A candidate's family should be eager to participate. When Dr Steinberg said she didn't want to campaign, she was pushing the envelope as far as the autonomy of the First Lady goes," says Mr Gould.
"This reflects the ambivalent attitude Americans have about the role of women in society still and the additional assumptions about their inferiority."
However other First Lady scholars believe there is scope within the role of the First Lady for ambitious and independent-minded women to prove themselves.
Myra Gutin, who has taught a course on First Ladies and written books on the subject, believes Dr Steinberg may not have given the institution as much credit as it is due.
"We've never had a professional First Lady before. Dr Steinberg says she would like to continue practising as a doctor if her husband became president. It would be difficult but I think it could be done," she told BBC News Online.
"There is no First Lady mould - it is a position that can accommodate anyone. Since Eleanor Roosevelt, we had the most active first lady in Hillary Clinton and now we have Laura Bush, who is one of the least active."
Hillary Clinton, a lawyer, gave up practising when her husband became president. Nonetheless, her White House work is widely seen as having prompted a backlash against her.
Her unpopularity with many Americans was not because she was active, Ms Gutin says. It was because she crossed the line and was active in areas of public policy.
"A First Lady can be active in the things that we might think of as more traditional feminine concerns. For example Lady Bird Johnson was interested in environmentalism and Roslyn Carter with mental health.
"The role of First Lady is not a stifling role - a woman in that position has to do with the job whatever she wants. Laura Bush has specific interests in education and literacy but has not gone as far as she could have done in promoting them."
Ms Gutin says she believes Ms Heinz Kerry is the sort of person who would seize the podium afforded her by her office to carry out a lot of good works.
Ms Heinz Kerry has devoted herself to overseeing and revamping the billion-dollar Heinz family endowments and has been described by the New York Times as one of America's leading philanthropists.
She has been showered with awards for her efforts on behalf of the environment, education, women, children, health issues and the arts.
In a recent interview, Ms Heinz Kerry criticised people who had asked her what existing model of First Lady she would follow if her husband's political ambitions were successful.
"I'm going to be me," she said. "I will continue to do my work. Just because a woman is a spouse she shouldn't be expected to look one way or act one way.
"I'm surprised sometimes that in America, a liberated country, we expect the wife of a president of the United States to be, in essence, a modern chattel. It's not right."