Lauren Camera of U.S. News & World Report discusses a little-noticed, and potentially troubling, trend: Dozens of cities nationwide have broken off from their counties to create new school districts, increasing student segregation by race, ethnicity, and family income. What are the implications of a recent U.S. district court ruling in Alabama that allowed such a move? Which states have laws on the books to permit public school secessions?  How will the Trump administration respond to these situations when civil rights concerns are raised? And what can be learned from a new data tool that examines equity in school funding?