From time to time during this primary, I've wondered about Obama's mama. In a race that was so much about biography, about beliefs rooted in her son's "DNA," she's made only cameo appearances.

She was the "mother from Kansas" balanced alliteratively with the "father from Kenya." Or she was the white parent whose genes combined with the black parent. Or she was the woman dying of cancer "more worried about paying her medical bills than getting well." And on Tuesday night when her son all but sewed up the nomination, she appeared again as the "single parent who had to go on food stamps at one point."

I have been thinking of her not just because it's nearly Mother's Day but because Obama will soon have to reach out to Hillary's supporters, especially to women of a certain age who attached their hopes to having a woman in the White House. Obama has not yet had a "gender conversation" with those women.

What better link does he have than his mother, Stanley Ann Dunham, the girl whose own father expected and wanted a boy child? Ann Dunham, a nonconformist, a woman of the world who traveled a trajectory of change so associated with Hillary's generation?

Last week, my eye lit on an odd correction in The New York Times. It read: "The assertion that Mr. Obama had 'never known' his Kenyan father should have been that he had 'barely known' him." Surely it was a distinction without a difference.

It's no surprise that Obama wrote an entire memoir dedicated to his "barely known" parent: "Dreams from My Father." Single mothers can tell you how much time and energy their children spend on the absent parent. Especially when the world identifies the son by the race of this father.

It was only after his mother's death that he wrote in a new preface, "I think sometimes that had I known she would not survive her illness, I might have written a different book — less a meditation on the absent parent, more a celebration of the one who was the single constant in my life." He added that "she was the kindest, most generous spirit I have ever known, and that what is best in me I owe to her."

From all accounts, this daughter of a family that kept traveling west in restless pursuit of the American dream took no part in Eisenhower-era conformity. She was a teenager in Hawai'i when she fell for the charismatic Kenyan in her Russian class and married him six months before her son was born. This was a time when interracial marriage was still illegal in parts of the country.

The rest of the story is known: a divorce, a marriage to an Indonesian, a second divorce. She was a mother who kept her children focused as well as fed. But what's less known is the woman in her own right, the one who became an anthropologist, the woman who spent years as the respected head of research for Women's World Banking, bringing micro-financing to poor people in Indonesia.

Nancy Barry, who was the head of Women's World Banking and knew Ann well, has been bewildered by the way she's been reduced to a stick figure. "She was stubborn, hard core, decisive, convincing, deep-thinking, rigorous in her analysis," says Barry. "When I hear Barack talking about how we are not red states, blue states but the United States, I think he gets that from his mother. The other core capability he gets from her is the desire for healing."

Indeed, the Obama we see may be the offspring of "Dreams from My Mother."

If Ann were alive today she would be the age of Hillary Clinton's most devoted demographic. She would be among those women who have gone through enormous transitions, making and remaking the female script. Dreaming big.

I am not suggesting Obama drag out his mama as a prop. But he's staked his case for the presidency on his ability to bridge racial, cultural, party divides, to lead a post-partisan America. He's described how the root of this desire is in his DNA. Now he's faced with another divide: women who identified their success with Hillary's and who are unsure they will vote for him.

What better way to begin reaching out, holding the "gender conversation," showing women he "gets it" than by sharing the dreams he inherited and the dreams he understands. The dreams from his mother. A girl named Stanley.

Ellen Goodman is a columnist for The Boston Globe. Reach her at ellengoodman@globe.com.