I have been thinking about Ann Dunham's other child, the girl child, the one she had with her second husband.

Maya Soetoro-Ng is now a 36-year-old teacher who describes herself as "half white, half Asian ... a hybrid." She is a Buddhist, married to a Chinese-Canadian, the mother of a 2-year-old and a woman who is so routinely identified as a Latina that she learned Spanish.

This daughter lives in Hawai'i, a state where nearly a quarter of the citizens check off two racial boxes or more on the Census Bureau questionnaire. She says that people marvel at her family, whose "complexity mirrors to a great extent the complexity of many families in this country and world today."

I've been thinking of Maya because her brother, Barack Obama, is running for president. And he is running to be the first African-American president.

So when asked whether she, the "hybrid," thought of her brother as "black," Maya said, "Yes, because that is how he has named himself. Each of us has a right to name ourselves as we will."

This business of naming ourselves, this question of culture and multiculture, racial and multiracial identity, keeps coming up in the presidential race. On the way to Iowa, Obama was routinely described as the candidate who transcended race. His understanding of the world was located broadly in his life.

Before the first vote, he said, "I think that if you can tell people, 'We have a president in the White House who still has a grandmother living in a hut on the shores of Lake Victoria and has a sister who's half-Indonesian, married to a Chinese-Canadian,' then they're going to think he may have a better sense of what's going on in our lives and in our country. And they'd be right."

If this was an appealing story to many, there were also African-Americans who wondered if Obama was "black enough." But somewhere between Iowa and South Carolina, race wasn't transcended. It was plumbed and polled and analyzed. The headlines and speeches hummed with racial undertones.

This wasn't surprising politics in South Carolina, a state where 29 percent of the population and half the Democratic voters are black. It is also a state where less than 1 percent of the population identifies itself as multiracial in the census questionnaire. This vast biological understatement may be an indication of the pressure to pick a "name" in a world where remnants of the old, pernicious "one-drop rule" still linger.

In South Carolina, Obama, who carries the DNA of slaveholders and Kenyans and even — heaven help him — Dick Cheney, became "black enough." It's not that he slipped from one brotherhood to another. Obama is no phony. The identity quest, which he described with such thoughtful and intimate honesty in "Dreams From My Father," is real.

Yet his personal and now political journey describes something else in our own increasingly multicultural world. For families as diverse as that of Maya and Barack, there remains the push to "name" yourself along with the reluctance to divide yourself.

How often are children of multiracial families asked, "What are you?" Stanford's Shelby Steele, himself the son of a white mother and black father, writes that what people really want to know "is what it is like to have no race to go home to at night. We commonly think of race as a kind of home, a place where they have to take you in; and it seems the very stuff of alienation to live without solid footing in such a home."

But for a growing number of Americans, especially children, home is not one race or ethnicity, if it ever was. Home is where — and who — your family is.

The children of what we label "mixed marriages" — ethnic, religious or racial — are often assumed to be torn by divided loyalties and identities. Yet the children that I have known may also — more so — be natural mediators, translators, connective tissue between multiple worlds.

Obama once described the tension African-American politicians feel between "speaking in universal terms and speaking in race-specific terms." In this campaign we see that tension between his "name" and his "home." And as this plays out on the national stage, we are also witnessing the challenge for an increasing number of multicultural families who try to build identities that are not contained by someone's view of "what we are."

Maya Soetoro-Ng described her mother as someone who "thought of life as sort of this beautiful tapestry, full of possibilities." Whatever this campaign brings, her children are living a reality out loud that is far more like that tapestry than it is like the neat little boxes on the Census Bureau forms.

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