Alas, the Eric Holder era is over. But critics who think his departure means normalcy will return haven’t been paying attention. Mr. Holder was President Obama’s point man for fundamentally transforming the country, and he did his job well. At the center of Mr. Holder’s transformative agenda was race. Race has always occupied Mr. Holder’s attention; he once said, “There’s a common cause that bonds the black United States attorney with the black criminal.” In what could have been a presidency where race faded into America’s rear-view mirror, Mr. Holder turned race into the road map. It all started in...