Heinz Kerry apologized later in the day, saying she had forgotten about Bush's 10 years as a teacher and librarian. She called the first lady to make amends.
The wife of Democratic presidential nominee Sen. John F. Kerry made the original remark in an interview with USA Today published Wednesday. She was asked to explain differences between herself and Laura Bush.
"Well, you know, I don't know Laura Bush. But she seems to be calm, and she has a sparkle in her eye, which is good," Heinz Kerry said. "But I don't know that she's ever had a real job -- I mean, since she's been grown up. So her experience and her validation comes from important things, but different things."
Heinz Kerry saw her own age, 66, as a plus. "I'm older, and my validation of what I do and what I believe and my experience is a little bit bigger -- because I'm older, and I've had different experiences. And it's not a criticism of her," she said. "It's just, you know, what life is about."
The Bush campaign criticized Heinz Kerry for appearing to draw a distinction between women who work in the home, and those who work outside the home.
"Well, I think it's very nice that she apologized, but in some ways the apology almost made the comment worse, because she seems to have forgotten that being a mother is a real job," Karen Hughes, an advisor to President Bush, said on CNN's "Inside Politics."
She said Heinz Kerry's comments reflected an "unfortunate mind-set that seeks to divide women based on whether you work at home or you whether you work outside the home. I've done both, and so has Laura Bush. And both are difficult, and both are rewarding."
Heinz Kerry issued a statement and called Laura Bush to apologize personally.
Heinz Kerry did not reach her, but spoke to her chief of staff, said Sarah Gegenheimer, a spokeswoman for Heinz Kerry.
"I had forgotten that Mrs. Bush had worked as a schoolteacher and librarian, and there couldn't be a more important job than teaching our children," Heinz Kerry said in the statement. "I appreciate and honor Mrs. Bush's service to the country as a first lady, and am sincerely sorry I had not remembered her important work in the past."
Laura Bush appreciated the phone call and empathized with Heinz Kerry over the public scrutiny wives of the candidates face, said Gordon Johndroe, the first lady's spokesman.
"Mrs. Bush is proud of her time as a public schoolteacher and librarian, raising a family and serving as first lady, but she also knows that some days can be longer than others out on the campaign trail when your husband is running for president," Johndroe said.
Both women had jobs in the workforce before marrying politicians and raising children.
Laura Bush worked in the Texas public schools until 1977, when she married George W. Bush. She has become an advocate of literacy.
Heinz Kerry was an interpreter for the United Nations in the 1960s. She married John Heinz, heir to the Heinz ketchup fortune and a future senator from Pennsylvania, in 1966. After he died in 1991, she became head of the Howard Heinz Endowment and the Heinz Family Philanthropies. She married Kerry in 1995.
Heinz Kerry has said that as a young woman, she never intended to have a full-time job.
"I had no ambition," she told the Pittsburgh Post-Gazette last fall. "I thought of myself as being married and having children, which is what all the ladies did."
At a rally Wednesday at Carnegie Mellon University in Pittsburgh, Kerry said of his wife: "What I love about her is what America has come to love about her -- this is a woman who tells what's on her mind and tells the truth to the American people."
As Bush and Kerry scramble to claim the few remaining undecided voters, especially women, even seemingly minor gaffes can become magnified, said Karen O'Connor, director of the Women and Politics Institute at American University in Washington.
"I am certain the Kerry campaign is just cringing that this came out this late in the day, at a time when Kerry has got to appeal to women," O'Connor said. "They're battling for just the kind of women who've just been insulted."
Times staff writers Edwin Chen and Matea Gold contributed to this report.