Chief Justice John Roberts began his tenure as Chief Justice of the United States in 2005. At approximately 17 years, he currently ranks as the seventh longest tenure as chief. In two years, he will be third, after John Marshall and Roger Taney. Whether his legacy needs to wait is an open question.Legacy formingRoberts will in the next six months pass Warren Burger and Charles Evans Hughes to become the fifth longest serving chief justice (a few justices served as associates and then chief longer, but did not hold the …