Who can explain the mystery?

Isn’t it remarkable that despite the fact that everyone there so values diversity and agrees that it is the most important aspect of education, the San Francisco schools are highly segregated?

Each January, parents across San Francisco rank their preferences for public schools. By June, most get their children into their first choices, and almost three-quarters get one of their choices.

A majority of families may be satisfied with the outcome, but the student assignment system is failing to meet its No. 1 goal, which the San Francisco Unified School District has struggled to achieve since the 1960s: classroom diversity.

Since 2010, the year before the current policy went into effect, the number of San Francisco’s 115 public schools dominated by one race has climbed significantly. Six in 10 have simple majorities of one racial group. In almost one-fourth, 60 percent or more of the students belong to one racial group, which administrators say makes them “racially isolated.” That described 28 schools in 2013–2014, up from 23 in 2010–2011, according to the district.

But the San Francisco Public Press has found the problem may be even more stark: If Asian and Filipino students are counted together — the standard used by the Census — together the number of racially isolated schools in the last school year rose to 39.

The drive toward racial isolation in the district parallels a larger trend in the city: With many wealthier families opting for private alternatives, the public school system is becoming racially and economically isolated from the city as a whole.

Why does it matter whether schools are diverse? One reason is academic performance. Recent studies from Stanford and the University of California, Berkeley, show that many students do much better on tests when placed in integrated classrooms, and that all kids are much less likely to grow up with racial stereotypes and prejudices. Far from being opposed to each other, excellence and diversity go hand in hand.

How did this resegregation of schools happen in a city where almost everyone from district leaders to parents supports the ideal of diversity?

And they’ve got studies show and everything! How did this happen to such a nice group of diversity-loving liberals? It’s almost as if… parents are choosing something other than diversity?