The last conventional public school in the New Orleans Recovery District closed last month, a harbinger of what may be in store in systems across the country. “Apparently, this model means taking education out of the public realm and putting it into the hands of private, non-profit boards and for-profit corporations,” said Karran Harper Royal, a parent advocate with the city’s Coalition for Community Schools, one of several groups that have filed a civil rights suit against the district and the Louisiana Board of Education. “It seems that white kids are disproportionately taking up the seats in the A- and B-rated schools,” while Black children are clustered in failing schools, said Ms. Harper Royal. “After all these years, we’re back in a segregated school system, only now it is also along class lines.”