Similar patterns have emerged in New York City, where the scores of charters dotting the city display disparities in the enrollments of English language learners, homeless and special education students.

Yet charters, which operate with government support but are granted special autonomy, have been celebrated for lifting up disadvantaged students. The Obama administration has held up the Harlem Children's Zone as a national model for fostering achievement in poor communities of color.

A study by Stanford University researchers found that English language learners and students living in poverty tend to perform better in charter schools, and some schools "seem to have developed expertise in serving [disadvantaged] communities.” At the same time, “For Blacks and Hispanics, their learning gains are significantly worse than that of their traditional school twins.”

The mixed report card suggests that since they have the freedom to experiment, charters range widely in their programming and standards, for better or worse.

The problem is that creating a special class of public schools can put diversity and equality at odds with each other. Immigrant parents may be shut out because they don't understand the application process. Meanwhile, charters are known for resisting teacher unions, which means they drive segregation not only in the student population but in the school workforce as well.

The charter school push is also suspect in light of the White House's continued fixation on standardized testing—a decidedly non-innovative approach to judging schools that are being pressured to innovate.

Charter schools, especially those run by for-profit companies, smack of the kind of corporatist model that many progressives loathe. But the promise of freedom from bureaucracy is alluring for struggling communities who want greater control over their children's educational futures.

Yet, if the point is to diverge from the educational status quo—whether it's through ethnic “niche” programming (popular and controversial in Minnesota schools), or using an unorthodox teaching approach, or hiring non-union staff—then can they be expected to fulfill the universal mission of public education: giving all students equal opportunity?

Education historian Diane Ravitch says the question isn't regular versus charter schools, but an issue of social priorities:

We can't solve our problems by handing them off to businesses and community groups. Some schools will claim success by excluding the students who are hardest to educate; others will claim success by drilling children endlessly on test-taking skills.

What should we do? We must strengthen — not abandon — public education....

We evade our responsibility to improve public education by privatizing public schools. In doing so, we undermine the egalitarian promise of public education, thus guaranteeing that many children will continue to be left behind.

Even a charter school with a social mission of promoting economic and racial equity still runs up against the limits posed by selectivity and exclusion. The rush to expand this model across the country may renew, and redefine, the question of separate but equal.

Image: Block Magazine