Last week, Melissa Harris-Lacewell wrote an insightful column, "Black by Choice," about President Obama’s having checked the box marked "Black, African American or Negro" on his Census form. As she notes, despite the way his complex heritage both disrupts "standard definitions of blackness" and creates "a definitional crisis for whiteness," in American culture "having a white parent has never meant becoming white" if one also has an African-descended parent.

When I read her piece, I was in a Columbia University faculty lounge, half listening to interesting people grumble interestingly about being asked to fill out another kind of census: the voluntary questionnaire, including self-identification of race and ethnicity, requested by the Integrated Postsecondary Education Data System. This accounting, which gathers a broad spectrum of information about colleges and universities, is compiled by the Department of Education. The results are public record–the most ubiquitous reference to them being the profiles one finds in the myriad guides for prospective students. The racial part of the inquiry also grows out of the monitoring of federal grants: schools that are entirely segregated by race raise concerns about eligibility for federal funds. In other words, it is a questionnaire framed by the need to remediate historical separation, inequity and stigma.

What piqued my attention to these half-heard conversations was their inverse relation to the phenomenon of Obama’s "choice." Everyone but me in the lounge was white, or would pass as such. But not one of them wanted to choose "white" as their identity. They were putting down descriptors like "mutt" or "human-colored" or "neutral" or "sallow." They were completely squeamish about describing themselves in racial or ethnic terms, and I was curious enough about the varied reasons for that resistance to join in the conversation.

For one person, it was a matter of science: "Race has no biological basis!" To him, it seemed race was all about bad biology; the power of it as a demographic and social force seemed entirely "imaginary." Another colleague described herself as Jewish: "I could never see myself as just white." When I asked her why she didn’t just write in "Jewish," she acknowledged a deep ambivalence about putting that on any official form. She’s the child of Holocaust survivors, and although she said she doesn’t distrust the US government or think that this form–used to patrol against discrimination–bears any resemblance to a yellow star, she admitted that she remains hesitant and torn. Yet another colleague objected to the question of race being asked under any circumstances, even acknowledging its power as a social construction: "I’m colorblind," he insisted. "Buff-beige is a color," I pointed out, referring to what he’d written in the box. "We’re never going to get past all this, unless we resist the usual categories," he said.

I understand the desire to unsettle habitual categories, but I can’t help thinking how much less leeway there is for African-Americans to "take a pass": most people who appear phenotypically "black" enjoy neither the privilege nor the inclination to play around on a government form designed to track and remediate generations of prejudice. To be visibly black in this culture is to feel race every day–one can’t forget it entirely when walking down the street. You’re fingered, inescapably tagged–boxed in not by the form but by collective presumptions and cultural prejudgments–about beauty, criminality, intelligence, manners, articulateness, merit, health and contagion. That’s the larger meaning of a social construction, after all: it has walls.

And so, while I understand the specific hesitations of my friends, I wonder if there’s not a larger force at work. Reading media reports of national controversies about collecting Census data, I’m struck by how often it is white people who seem to struggle most with identifying themselves in any way that is coherent or useful to demographers. On one end, there are liberals who make much of not wanting to be "confined" by race: Moi? A political category? Pass. On the other end, some right-leaning whites seem convinced that unless they report that they’re some kind of minority–usually dragging some poor, imagined Native American out of the closet–they’ll miss out on putative "government handouts." Even those on the extreme right who are deeply committed to "white pride" seem to eschew putting that on the Census, urging fellow travelers to write in "Confederate American."

Sociologists Jennifer Lee and Frank Bean, in their excellent paper "Reinventing the Color Line: Immigration and America’s New Racial/Ethnic Divide," have written about how Asian and Latino immigrants are crafting their racial identity over time. They observe that earlier groups of European immigrants who were once stigmatized as "non-white"–like Irish or Italians or Jews–over time assimilated into "whiteness." Lee and Bean point out that newer migrants from Asia, Latin America and the Caribbean are also assimilating into the dominant identity group but in ways that are shifting the racial paradigm from "white/non-white" to "black/non-black."

American identity has always been a composite creation, produced by multiple generations of miscegenation, so that any origin myth is repeatedly shattered and reconstructed in diasporic waves. But in the context of public counts like the Census or the Department of Education’s survey, a new "innocence" of self-identification seems to be pushing us toward an official narrative that is less empirical than epic, where our neighborhoods and institutions are awash with Indo-European nomads, Apache warriors and "neutral," "putty-faced" "mongrels." But this dreamy world of exotically configured ethnics, so assimilative and accommodating, so playfully shape-shifting–is nonetheless premised on that still-unyielding categorical divide: "not black."