Nearly a week after George Zimmerman was found not guilty of killing Trayvon Martin, President Obama walked into the press briefing room and shocked observers by saying that “Trayvon could have been me.” He talked personally and poignantly about his experiences and pointed to intra-racial violence as equally serious and precarious for black boys. He offered no sweeping policy changes or legislative agendas; he saw them as futile. Instead, he suggested that prejudice would be...