The U.S. Supreme Court’s June 25 decision in Horne v. Flores gave newly elected governors and mayors something to cheer about. The high court’s rationale opens a door for officials in every state and most large cities to get out from ancient decrees controlling how they run many kinds of programs.

There are thousands of old decrees. For example, decades-old decrees dictate how New York City runs special education, homeless shelters, foster care and dozens of other programs. Typically, incumbent mayors agreed to these decrees, but, once entered, they become mandatory obligations on their successors in office. One incoming mayor after another has had to struggle with the plans, bargains, trade­offs and milestones agreed to long before regardless of whether they make sense in light of the lessons of experience.