President Bill Clinton nominated Campbell on September 2, 1997, to a fifteen-year term as an associate judge on the Superior Court of the District of Columbia to the seat vacated by John H. Suda. On October 30, 1997, the Senate Committee on Governmental Affairs held a hearing on his nomination. On November 5, 1997, the Committee reported his nomination favorably to the senate floor. On November 7, 1997, the full United States Senate confirmed his nomination by voice vote.[5]
On September 11, 2012, the Commission on Judicial Disabilities and Tenure recommended that President Obama reappoint him to second fifteen-year term as a judge on the D.C. Superior Court.[6] Campbell retired from the court on May 19, 2023.[7] Starting in August 2023, he was evaluated for an appointment as a senior judge and assumed office the following year.[7]