That's the title of this Wall Street Journal report:
For much of the 20th century, the proportion of whites shrank in most U.S. cities. In recent years the decline has slowed considerably -- and in some significant cases has reversed. Between 2000 and 2006, eight of the 50 largest cities, including Boston, Seattle and San Francisco, saw the proportion of whites increase, according to Census figures. The previous decade, only three cities saw increases.