One of the least-known phenomena-outside of California, at least-is the incursions Mexicans have made into black territory-it's particularly pronounced in inner cities. That was an intentional side-effect of illegal immigration - big, politically connected inner-city property owners/developers have watched their values increase steadily as Mexicans have displaced black populations. Urban renewal, on the cheap.
Yeah, Steve Sailer has written about that facet of immigration-usually while critiquing white Hispanic faux liberal Matt Yglesias-before.