Non-white populations continue to penetrate more areas of the country

A March 2006 Brookings Institution study reports that between 2000 and 2004, “Hispanic and Asian populations are spreading out from their traditional metropolitan centers, while the shift of blacks toward the South is accelerating.”
It goes on to report that

Of the nation’s 361 metropolitan areas, 111 registered declines in white population from 2000 to 2004, with the largest absolute losses occurring in New York, San Francisco, and Los Angeles. Declines were greatest in coastal metropolitan areas and economically stagnant parts of the country. More so than for minority groups, white population growth has dispersed towards smaller-sized areas.

Minorities contributed the majority of population gains in the nation’s fastest-growing metropolitan areas and central metropolitan counties from 2000 to 2004. Minority groups remain the demographic lifeblood of inner counties in older metropolitan areas, but they are increasingly fueling growth in fast-growing outer suburban and “exurban” counties as well.

Hispanic, Asian, and black populations continue to migrate to, and expand their presence in, new destinations. They are increasingly living in suburbs, in rapidly growing job centers in the South and West, and in more affordable areas adjacent to higher-priced coastal metro areas. The wider dispersal of minority populations signifies the broadening relevance of policies aimed at more diverse, including immigrant, communities.

The study: Diversity Spreads Out: Metropolitan Shifts in Hispanic, Asian, and Black Populations Since 2000, by William H. Frey, March 2006
Further findings:

The Los Angeles and New York metropolitan areas contained 23 percent of the nation’s Hispanic population in 2004, down from 30 percent in 1990. Meanwhile, interior California areas such as Riverside and Stockton gained significant numbers of Hispanics and Asians. Fully 56 percent of the nation’s blacks now reside in the South, a region that has garnered 72 percent of the increase in that group’s population since 2000.

The fastest growing metro areas for each minority group in 2000–2004 are no longer unique, but closely parallel the fastest growing areas in the nation. National growth centers such as Las Vegas, Atlanta, Orlando, and Phoenix are now prominent centers of minority population growth as well. Still, Hispanics, Asians, and blacks remain more likely to reside in large metropolitan areas than the population as a whole.

A strong multi-minority presence characterizes 18 large “melting pot” metro areas, and 27 large metro areas now have “majority minority” child populations. Because the nation’s child population is more racially diverse than its adult population, in nearly one-third of all large metro areas—including Washington, D.C., Chicago, Phoenix, and Atlanta—fewer than half of all people under age 15 are white.