A June 3, 2017, editorial in the Boston Globe mentions the situation with the Silver Hill Horace Mann Charter School.
"Back in 2006, in its pre-charter existence, the K-5 school was underperforming and facing a possible state takeover. The approach to fixing those problems was to transform the school into an automatically unionized Horace Mann charter, thereby giving it more latitude to set its own course. By 2013, Silver Hill had made enough progress to win Level 1 status. That is, a spot in the state’s top school tier."