Rankin served as Solicitor General from 1956 to 1961. In 1952, Rankin managed the Dwight Eisenhower for President campaign in Nebraska and in 1953, Eisenhower selected Rankin to serve as United States Assistant Attorney General. In 1953, he was appointed Assistant Attorney General in charge of the Office of Legal Counsel. In this capacity, Rankin may best be remembered for arguing in favor of the African-American plaintiffs in Brown v. Board of Education, advocating that the doctrine of "separate-but-equal" facilities for blacks and whites was unconstitutional. After the Supreme Court's ruling in Brown, Rankin argued in a presentation before the Court that the effort to desegregate schools should take place gradually in an effort to avoid any violence that might arise from the decision. Accordingly, he suggested the plan by which local school districts submitted desegregation plans to federal judges in their states. In addition, Rankin argued a great range of other important cases before the Supreme Court. He was instrumental in resolving conflicting claims among Western states to the Colorado River, and in establishing a balance of federal and state jurisdictions in offshore oil drilling. On August 14, 1956, Rankin was appointed U.S. Solicitor General. In response to lawsuits in many states arising out of legislative reapportionment fights, he developed the Justice Department's position that led to the principle of one man, one vote. After serving as solicitor general from August 1956 to January 1961, Rankin represented the American Civil Liberties Union in advancing the landmark case, Gideon v. Wainwright, solidifying the right of an indigent person accused of a crime to have legal counsel at public expense. Following President John F. Kennedy's assassination, and the appointment of Chief Justice Warren to serve as the Chairman of a Presidential Commission to ascertain the truth about Dallas, Rankin was selected by Chief Justice Warren to serve as General Counsel in the inquiry that concluded that Lee Harvey Oswald had acted alone in killing President Kennedy. According to Edward Epstein's "Inquest", Rankin was primarily an administrator and lent a decent guiding hand in shaping the investigation. The 14 man legal staff was split into seven two-man teams, each of which handled a separate area of the investigation Each team was responsible for a separate area of the investigation, and, essentially, submitted a separate chapter of the Warren Report. The attorney who tied it all together—who did much of the "heavy lifting" and who Epstein credited with redrafting and editing the commission's voluminous report into a work of polished prose—was Norman Redlich. Subsequently, Rankin practiced law in New York City until the 1970s, working seven years as the New York City Corporation Counsel.
Later life
Upon retirement, Rankin and his wife of 63 years, Gertrude, moved to Weston, Connecticut, where they had a summer home. In 1993, they relocated to their home in Los Gatos, California. Mr. and Mrs. Rankin had two sons, James Jr. and Roger C., and one daughter, Sara Stadler; six grandchildren, Todd, Stephanie, Russell, Andrew, Amy, and Justin; and four great-grandchildren, Camden, Thomas, Hannah, and Faith. Rankin died on June 26, 1996 in Santa Cruz, California. He is interred at Santa Cruz Memorial Park in Santa Cruz.
