A year ago, Arne Duncan was known as a long-serving urban district chief who had used his collegial management style to push innovation and close failing schools in Chicago. This week, he enters his second year as U.S. secretary of education pursuing a similar national policy agenda that could place him among the most influential leaders in his…

Chicago is embarking on a major initiative to convert at least 10 percent of its schools into small schools, most of which will be run by private operators. Mayor Richard M. Daley portrayed his plan, called Renaissance 2010, as a way to "shake up the system," introduce fresh ideas that could save its lowest-performing schools, and…