The first Democratic debate brought renewed attention to busing as a tool of school desegregation. We spoke to a colleague about what the conversation has been missing. Guest: Nikole Hannah-Jones, who writes about racial injustice for The New York Times Magazine. For more information on today’s episode, visit nytimes.com/thedaily.  Background reading: “The school bus, treasured when it was serving as a tool of segregation, became reviled only when it transformed into a tool of integration,” Nikole Hannah-Jones writes in a news analysis.