How 'the great dissenter' John Harlan influenced SCOTUS

In the Supreme Court's voting law decision Thursday, Justice Elena Kagan dissented and said the majority undermined the voting rights act by upholding Arizona's laws. John Yang looks at another justice who delivered historic dissents during the Jim Crow era, John Harlan, whose career is documented in Peter Canellos' "The Great Dissenter: The Story of John Marshall Harlan, America's Judicial Hero."