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,[5] which solidified the right of an indigent person accused of a crime to have legal counsel at public expense.

According to author Edward Epstein, Rankin was primarily an administrator and lent a guiding hand in shaping the investigation.

The 14-man legal staff was divided into seven two-man teams, each of which handled a separate area of the investigation and contributed a chapter to the commission's final report.

This article incorporates public domain material from websites or documents of the Solicitor General of the United States.