When Vicky Key looks at Barack Obama, she sees someone like her - not black, not white, but mixed.
"I feel for him," says Key, 20, a sophomore at the University of Maryland, College Park, where she is active in the Multiracial and Biracial Student Association. "Because of being mixed, the issue comes up of if he is trying to be black or white. I face that challenge every day. People look at you and judge you by how you look."
As products of mixed-race marriages, Obama and Key are in a what appears to be a fast-growing segment of the American population. The 2000 Census was the first to allow people to choose more than one racial category to describe themselves and more than 7 million did just that - yet some experts say even that total is too low. "That's just the tip of the iceberg," says Matthew Garcia of the Center for the Study of Race and Ethnicity in America at Brown University.
Obama's emergence could accelerate the challenge to accepted racial categories and lead to what social historians call a post-racial era, in politics and, indeed, in all of American life. Today, many multi-racial Americans are helping to forge that new era.
Brian Knight, a Baltimore lawyer, has not had problems with living in this state of flux.
"I was aware of what I was and wasn't growing up," says Knight, whose father is from the Caribbean, his mother from Germany. "In white European circles, it was clear I was not white. In African-American circles, I was not perceived as African-American. I was mostly mistaken as Hispanic. ... "
"I think you become aware that you kind of don't fit into these groups," he says. "I tended to be comfortable with anyone, anytime."
Warren Kelley, assistant vice president of student affairs at College Park and adviser of the Multiracial and Biracial Student Association, says this comfort level can give mixed-race people an advantage.
"We learn to deal competently with different cultures," says Kelley, who has a black father and a Japanese mother. He adds, "I think if you grow up in that kind of family, you see how malleable race is while everything in society treats race as a big, firm wall."
But Key says there is another side to that malleability. "I had a hard time trying to figure out who I was. People were always trying to tell me who I was supposed to be. It is hard to explain. I have gone through a lot of racial problems."
For decades, scientists such as sociologists and biologists have called race a social construct - categories created by societies to catalog people, rather than a biological fact. Experts note that many people have vested interests in those categories, so breaking them down may meet with resistance.
"I wish I could tell you I thought we were moving beyond these racial categories, but I think they are going to be with us for a long time," says Karen Kaufmann, an associate professor of government and politics at the University of Maryland, College Park.
To many, Obama is the perfect point person for an assault on these categories. Not only was his mother a white women from Kansas and his father a Kenyan, but Obama had an Indonesian stepfather and spent some childhood years in that country.
Garcia, who teaches a class on multi-racialism at Brown, says it is significant that Obama's youthful years in the United States were spent in Hawaii.
"In some ways, his arrival on the national scene marks the integration of Hawaiian sensitivity about race and interracial relationships into the continental United States," he says. "The whole concept of multi-racialism is very alive in Hawaii. It is the norm in many ways."
Obama makes clear in his 1995 memoir, Dreams of My Father, that he chose an African-American identity - just as golfer Tiger Woods chooses to celebrate his panoply of racial identities. But others say the choice was not totally in his hands.
Early in his campaign, Kaufmann notes, Obama was often accused of not being black enough. "One of his defenses was to half-joke that he was black enough when he tried to hail a cab in New York City," she says.
That anecdote, she notes, shows that race "is about how people's appearances get played out in social and economic and political heirarchies. On paper, he may not be black, but he walks through life experiencing it as a black man. ... People come to see themselves as others see them."
Knight agrees. "I think there is a debate around whether or not you can pick your race. Tiger Woods and me and my siblings may try, but the fact is, clearly we are not white. And we still live in a society that adheres to the 'one-drop' rule,'" he says, referring to archaic laws that defined a black person as one with a single drop of black blood in his veins, or one black ancestor on the family tree.
Katrina Bell McDonald, a sociologist at the Johns Hopkins University, says her fellow African-Americans may have their own take on the Illinois senator.
"To me, he is just a black boy who has done well," she says. "He's got a good head on his shoulders, he's picked a good companion, he's done well and makes us proud.
"I don't see him as a mixed-race person at all. That said, I think Barack is a lot of different things to a lot of different people. His mixed ancestry works with some people, embodying the melting pot image they have in their heads."
James Glass, who studies the psychology of politics at College Park, says one can sense in Obama's speeches the possibility of his transcending traditional racial categories.
"In the way he puts politics together, his connection with the audience, race has no meaning," he says.
"With him, people don't think they are seeing a political leader who is African-American, or a political leader who is half-white and half-African-American; they are seeing a political leader who articulates a point of view that encompassses the audience's intelligence."
That is what Knight sees in Obama, a politician who excites voters not because he is African-American, but because he has ideas that resonate with the American public.
"I think it is a generational issue," Knight says of Obama's appeal as a post-baby boomer candidate. "At least that is how he speaks to me personally. ... But almost every story about him has in its first few lines the extent of the African-American turnout.
"It makes me chuckle - as if that matters in Idaho and Minnesota and places like that. It's as if the journalists are stuck in that old analysis mode, are not sure how to handle this campaign."
Key of the University of Maryland thinks an Obama presidency would change views of race and biracialism. "I just hope people can look past his race and judge him on what he is trying to do for the country, while, at the same time, he can be a role model for minorities."
Yet traditional racial categories are very stubborn. They are embedded in laws designed to counter previous discrimination. In many cases, minority leaders opposed allowing people to declare more than one race on Census forms.
"Many traditional Democratic Party supporters hold onto very rigid racial definitions," Garcia says. "It has all sorts of implications for the way voting districts are construed, the way support for education is doled out, the way people are regarded when they come into schools, and such."
Parks says it is more than the law. "People still have emotional connections to these categories."
And often these categories do have meaning beyond the social construct. Ronald Walters says students in his racial politics class at the University of Maryland assumed race was obsolete.
"But when Katrina came along, the students were absolutely floored," he says of seeing so many black people clearly treated differently than whites. "They couldn't handle it because it was outside their frame of reference; they were not used to thinking in those racial terms.
Still, Garcia says the lingering emotional connection people have for racial categories might be beginning to die out.
"Young people have a very different sense of what race is in America," he says. "In their world, borrowing on my own experiences, the next generation is connecting with the idea that race is much more fluid than black and white, they are embracing the idea of multi-racialism."