Fix the Census" Archaic Racial Categories STARTING in 1790, and every 10 years since, the census has sorted the American population into distinct racial groups. Remarkably, a discredited relic of 18th-century science, the "five races of mankind," lives on in the 21st century. Today, the census calls these five races white; black; American Indian or Alaska Native; Asian; and Native Hawaiian or other Pacific Islander. The nation's founders put a hierarchical racial classification to political use: its premise of white supremacy justified, among other things, enslaving Africans, violent removal of Native Americans from their land, the colonization of Caribbean and Pacific islands, Jim Crow subjugation and the importation of cheap labor from China and Mexico. Of course, officially sanctioned discrimination was finally outlawed by civil rights legislation in 1964. The underlying demographic categories, however, were kept. Securing civil rights required statistics. Thus resulted an uneasy marriage of preposterous 18th-century racial classifications to legitimate 20th-century policy goals like fair electoral representation, anti-discrimination programs, school desegregation, bilingual education and affirmative action. But the demographic revolution since the immigration overhaul of 1965 has pushed the outdated (and politically constructed) notion of race to the breaking point. In June the Supreme Court struck down a core provision of the Voting Rights Act, taking note of changing demographics. I disagree with the court's ruling, but agree that society is changing. And our statistics must reflect those changes. Fast-growing population groups - mixed-race Americans, those with "hyphenated" identities, immigrants and their children, anyone under 30 - increasingly complain that the choices offered by the census are too limited, even ludicrous. Particularly tortured is the Census Bureau's designation, since 1970, of "Hispanic" as an ethnicity or origin, thereby compelling Hispanics to also choose a "race." In 2010, Hispanics were offered the option to select more than one race, but 37 percent opted for "some other race" - a telling indicator that the term itself is the problem. Indeed, anyone who filled in "some other race" that year was allocated to one or more of the five main groupings. Many absurdities have resulted. America has about 1.5 million immigrants from sub-Saharan Africa - some 3 percent of the nation's black population. Like President Obama's father, who was Kenyan, their experience differs vastly from that of African-Americans whose ancestors were enslaved, yet they are subsumed into the same category - one that, until this very year, continued to include the outdated term "Negro." The census considers Arabs white, along with non-Arabs like Turks and Kurds because they have origins in the Middle East or North Africa. Migrants from the former Soviet nations in Central Asia are lumped in as white along with descendants of New England pilgrims. An indigenous person from Peru, Bolivia or Guatemala is Hispanic, but if she "maintains tribal affiliation or community attachment," she might also be counted as part of a racial group that includes the Inupiat and Yupik peoples of Alaska. Are Australian immigrants whites or Pacific Islanders? The Census Bureau's own documents are unclear on this. The census has no second-generation question, leaving Congress to debate immigration reform with inadequate statistics about which new Americans are learning English, finishing school, living in segregated neighborhoods or staying out of jail. Social scientists closely track intermarriage as an indicator of assimilation, but the census reports intermarriage only among whites, blacks, Hispanics and others - overlooking unions between, say, Japanese and Chinese, Cubans and Mexicans, Nigerians and native-born blacks. These marriages may have as much to tell us about where the nation is headed as the rate at which whites intermarry. Much attention has been paid to the news that non-Hispanic whites now account for less than half of births in the United States and that deaths now exceed births among non-Hispanic whites. These projections are oversimplified and misleading because they rely on the outdated "five races" concept. The far more significant turning point is the shift from a nation of a few large racial blocs into a hybrid America of numerous nationalities, ethnicities and cultures, unprecedented in human history. It is this hybrid, multivalent, dynamic America that is not reflected in the census. We cannot, however, fix this at the expense of abandoning racial categories, which are still needed for legitimate policy purposes. Kenneth Prewitt, the director of the United States Census Bureau from 1998 to 2000, is a professor of public affairs at Columbia University and the author of "What Is Your Race? The Census and Our Flawed Effort to Classify Americans.