Thus, replacing a city’s blacks with immigrants would tend to lower local crime rates by as much as 90%, and during the 1990s American elites may have become increasingly aware of this important fact, together with the obvious implications for their quality of urban life and housing values. 

According to Census data, between 1990 and 2010 the number of Hispanics and Asians increased by one-third in Los Angeles, by nearly 50% in New York City, and by over 70% in Washington, D.C.  The inevitable result was to squeeze out much of the local black population, which declined, often substantially, in each location.  And all three cities experienced enormous drops in local crime, with homicide rates falling by 73%, 79%, and 72% respectively, perhaps partly as a result of these underlying demographic changes.  Meanwhile, the white population increasingly shifted toward the affluent, who were best able to afford the sharp rise in housing prices.  It is an undeniable fact that American elites, conservative and liberal alike, are today almost universally in favor of very high levels of immigration, and their possible recognition of the direct demographic impact upon their own urban circumstances may be an important but unspoken factor in shaping their views.