Attorney General Eric Holder’s announcement of significant changes in the Justice Department’s pursuit of mandatory minimum sentences highlights a new willingness on the part of the Obama administration to engage on issue of race. It’s the second public policy area touching on race where Holder — the nation’s first African American attorney general — has flexed his muscles in recent weeks. Just last month, he said Justice would challenge voter ID laws adopted in the aftermath of the Supreme Court's decision to gut a key provision of the Voting Rights Act. Holder’s actions come in conjunction with President Obama's recent...