Liberal lawyer and longtime Washington insider who helped found the Americans for Democratic Action and led the presidential commission on race relations whose report, in 1968, warned that the United States was “moving toward two societies — one black, one white, separate and unequal." Mr. Ginsburg arrived in Washington in 1935 and quickly emerged as one of the brightest of the New Dealers. He helped draft laws on price controls during World War II and served as an adviser on reorganizing the German economy after the Allied victory. In 1967, as race riots engulfed Detroit and Milwaukee, after similar disturbances in Los Angeles, Newark and Chicago, President Lyndon B. Johnson appointed Mr. Ginsburg executive director of the National Commission on Civil Disorders. Known as the Kerner Commission, after its chairman, Gov. Otto Kerner of Illinois, the panel was charged with seeking out the causes of the riots and proposing solutions. In the 1970s, Mr. Ginsburg successfully represented Henry A. Kissinger in his long battle to keep private the transcripts of his telephone conversations while serving as secretary of state and national security adviser under President Richard M. Nixon. Mr. Ginsburg graduated in 1932 from West Virginia University, where he studied economics and politics. Three years later, he earned a law degree at Harvard. With help from his mentor, Felix Frankfurter, soon to be a United States Supreme Court justice, Mr. Ginsburg found work with the Securities and Exchange Commission in Washington. He clerked for Justice William O. Douglas at the Supreme Court for a year but returned to the S.E.C. after war broke out in Europe. In April 1941 he became general counsel to the Office of Price Administration and Civilian Supply (called the Office of Price Administration after January 1942). Mr. Ginsburg enlisted in the Army as a private, driving trucks in a supply battalion, and rose to captain. After the war he served on the staff of Gen. Lucius D. Clay in Germany, where he attended the Potsdam Conference and the early Nuremberg war trials. In 1946 he founded the Washington law firm of Ginsburg & Leventhal, which later became Ginsburg, Feldman & Bress. It dissolved in 1998, and he joined Powell, Goldstein, from which he retired in 2007 at the age of 95. Mr. Ginsburg’s first two marriages ended in divorce. In addition to his son Mark, of Paris, he is survived by his wife, Marianne Lais Ginsburg; another son, Jonathan, of Chantilly, Va.; a daughter, Susan, of Alexandria; and two grandchildren.