Two of the prospective first ladies are managing life-threatening diseases. One would be the first woman of color with the title. A third recently completed her latest humanitarian trip, to Vietnam.
All but one of them are mothers, including of young children. One's a grandmother of 10, too.
Americans have a variety of women to get to know in the campaign, quite apart from the very well known former first lady who's running for president in her own right.
In a race marked by the spectacle of a two-term president, Bill Clinton, promoting wifefor the White House, these women carry on the tradition of spouse as potential first lady, but not always in traditional ways.
Elizabeth Edwards and Ann Romney talk about their incurable cancer (Edwards) and multiple sclerosis (Romney). Michelle Obama tells funny tales about the juggling she does to get two girls off to school and herself to work.
"First ladies, first kids. It helps us relate to them. It helps to humanize them," says Robert Watson, author of two books about first ladies and the director of American studies at Lynn University in Florida.
A look at seven of them:
She is the girl who, at 15, became smitten with an 18-year-oldand then waited for him while he went to college and then to France to complete traditional missionary service for the Mormon church.
As days turned to months and then years, his father, George, watched over Ann, an Episcopalian, and helped convert her to the Mormon faith. Then she went off to Brigham Young University to wait for her future husband.
They wed in 1969, three months after he came home.
She is one of the weapons the Romney campaign is using to appeal to the GOP's social conservatives by setting him apart from his major rivals, who are in second and third marriages, including two with significantly younger wives. On Monday, she posted her own Web site.
She told supporters at a campaign event that the biggest difference between them and her husband is that "he's had only one wife." She's also been introduced as Romney's starter wife and trophy wife "all in one" - another dig at the opposition.
The mother of five grown sons and grandmother of 10, Ann Romney, 57, has devoted her life to the men in it. She has said she was both satisfied and privileged to have been able to stay at home, but she also has talked about how "exasperating and overwhelming" it was to be the only female in a house overflowing with testosterone.
As first lady of Massachusetts, Ann Romney was active in teen pregnancy prevention and faith-based work with inner-city children. She was the administration's chief liaison to religious and faith-based social service organizations.
Nearly a decade ago, she began to feel numbness in her right leg. It spread, leaving her right side without feeling. There was fatigue, then depression, then self pity. Doctors diagnosed multiple sclerosis around Thanksgiving 1998.
She says the MS is in remission and she takes no medication to treat it. Instead, she relies on alternative and holistic treatments, such as her lifelong pursuit of horseback riding. "Joy therapy," she calls it.
Last year, she won a gold medal for the United States Dressage Federation at the Grand Prix level.
He impressed her nonetheless.
She married him nearly 15 years ago, never thinking she'd have to make a political speech, let alone live a life as a politician's wife. Her husband was, after all, a law professor and civil rights attorney in Chicago.
But Michelle Obama seems to have learned fast.
She was at first resistant to now-Sen.decision to run for president just two years into his first term. Now, she is his biggest booster - and a popular draw in her own right.
She builds him up by gently cutting him down to size, the celebrity candidate made human. "He's like, 'Mr. GQ' all of a sudden," she told a crowd. "He's got, like, five white shirts and three black suits, and all of a sudden, he's best-dressed."
But her remark last week that "If Barack doesn't win Iowa, it is just a dream," prompted a hasty clarification from the Obama campaign that he does not need to win the state to carry on.
Michelle Obama, 43, grew up in a working-class family on Chicago's South Side. Her father was a city employee; her mother stayed at home. After Princeton and Harvard Law School, she returned to Chicago and the law firm of Sidley and Austin, where she met her husband. She later worked for the mayor, then ran a nonprofit that trained young people for public service careers before landing at the University of Chicago Medical Center. She is vice president of community and external affairs.
On the campaign trail, Michelle Obama appeals to women who feel pulled in multiple directions by the twin pressures of career and family. She says that even she - a woman with a famous husband (who sometimes forgets to put away the butter), her own high-powered career and a million-dollar mansion - feels the same way, too.
Daughters Malia, 9, and Sasha, 6, travel with her when they aren't attending private school in Chicago. She limits her political travel and tries to get home in time to tuck them in at night when they aren't with her.
The experience has had its down sides. Michelle Obama has been criticized for serving on the board of TreeHouse Foods, Inc. The Illinois-based food company supplies Wal-Mart, whose labor practices her husband has criticized. She resigned in May, citing increased demands on her time.