Business.
The Left likes to peddle stereotypes. CEOs are large, overstuffed, pre-Splenda sugar barons smoking cigars as the white horses carry their carriage to the ball. Immigrants are, by definition, pooranddowntrodden products of failure-oriented cultures. Southerners this. New Yorkers that. Never can one be the other - at least as more than a token - and the Mason-Dixon line apparently still separates smart from backwater.
So explain to me how the senior management of an S&P 1500 company is named Gregorian, Melendrez, Ghaderi, and Le. Another company whose conference call I listened in on had a CFO who sounded like he grew up a couple of miles from the Duke Law School he attended (he did) and a CEO who sounded as though he had the same speech coach as Robert Loggia (he probably didn't).
I suspect all of this was accomplished without busing, although some forms of long-range transport were involved somewhere in the process. Contrary to liberal obsessions, most people just don't think about race on a moment-to-moment basis. Give 'em a decent education, an internal combustion engine, and some pavement, a reason to use them, and people are bound to mix.