The cause was complications from a stroke, his family said.
Mr. Dutton worked on John F. Kennedy's presidential campaign in 1960, and after the election he came to Washington to be on the White House staff. After serving a year as a presidential assistant, he became assistant secretary of state for Congressional relations.
He was a deputy national chairman of Lyndon B. Johnson's presidential campaign in 1964, and he was effectively Robert F. Kennedy's campaign manager in the Democratic primaries in 1968.
Among the other Democratic politicians that he worked for were Adlai E. Stevenson, Hubert H. Humphrey and George McGovern. He remained close to the Kennedy family and helped to develop the John F. Kennedy Library and the Robert F. Kennedy Memorial, a foundation.
In the 1970's, he was hired by the Saudi royal family to be their Washington consultant and lobbyist. Filings with the Justice Department show that he earned millions of dollars from the Saudis over the years.
Mr. Dutton was instrumental in winning government support for the sale of fighter planes to the Saudis in 1978 and radar planes in 1981. In 2002, records show, he received more than $500,000 to help manage the Saudis' public response to the attacks of Sept. 11, 2001.
Frederick Gary Dutton was born on June 16, 1923, in Julesburg, Colo., the son of a doctor. In 1930, his family moved to the San Francisco area, and he graduated from the University of California, Berkeley, and the Stanford University Law School.
Mr. Dutton was in the infantry in World War II. He was wounded in the Battle of the Bulge and received a Bronze Star and a Purple Heart. He was recalled into the Army in the Korean War to serve in the Judge Advocate General's Corps.
Shortly after he left the Army, Mr. Dutton became involved in politics in California. He was special counsel to the State Senate Judiciary Committee, chief assistant attorney general and chief of staff for Gov. Edmund G. Brown Sr.
In the Kennedy White House, Mr. Dutton was secretary to the cabinet and coordinator of domestic policy.
He began a law practice in Washington in 1965. Thanks to a friend from the Kennedy campaigns who was an executive for the Mobil Corporation, that company became one of his main clients.
Mr. Dutton's first marriage, to June Klingborg, ended in divorce. His second wife, Nancy Hogan Dutton, also became his law partner. In addition to her, he is survived by three children from his first marriage, Christopher, of San Anselmo, Calif.; Lisa, of Los Angeles; and Eve, of San Carlos, Calif.; two daughters from his second marriage, Stacy, of Philadelphia and Christina, of Washington; and seven grandchildren.
In an interview in 1978, Mr. Dutton said he was hired by the Saudis after Senator J. W. Fulbright, then the chairman of the Foreign Relations Committee, told Rawleigh Warner Jr., the chief executive of Mobil, that the Saudis did not "handle themselves well" in Washington. Mr. Warner passed the message and Mr. Dutton's name to the Saudi government.
Many of Mr. Dutton's duties for the Saudis revolved around multibillion-dollar arms sales and development projects. But others were more personal, like negotiating the purchase of an apartment for the Saudi foreign minister on Park Avenue in New York City and finding orthopedic chairs for ailing Saudi royalty.