Paul Vallas, the man who took over the troubled school systems of Chicago and then Philadelphia and upended them, stood before a crowd of New Orleans parents in a French Quarter courtyard earlier this summer and offered a promise. "This will be the greatest opportunity for educational entrepreneurs, charter schools, competition and parental choice in America," he said. Call it the silver lining: Hurricane Katrina washed away what was one of the nation's worst school systems and opened the path for energetic reformers who want to make New Orleans a laboratory of new ideas for urban schools .
Vallas is part...