A writer and Democratic political strategist who was Senator Robert F. Kennedy’s press secretary, directed Senator George S. McGovern’s losing 1972 presidential campaign and for six years was the president of National Public Radio. A scion of Hollywood, the son of Herman J. Mankiewicz, who wrote “Citizen Kane,” and the nephew of Joseph L. Mankiewicz, who directed “All About Eve,” he grew up with an Algonquin West round table in his Beverly Hills household, regaled by movie stars, famous writers and comedians like the Marx Brothers. He became a journalist and lawyer and, inspired by the Kennedys, went to Washington at the dawn of the New Frontier and took an executive position at the Peace Corps. What he encountered were assassinations, the Vietnam War and the Watergate scandals. His face became familiar to the nation in 1968, as he articulated Robert Kennedy’s campaign for the White House, conveyed whirlwind euphoria over the senator’s triumph in the California primary and then, within hours, grimly announced Mr. Kennedy’s death by an assassin’s bullets in Los Angeles. From 1977 to 1983, Mr. Mankiewicz was president of NPR, the federally financed network of news, public affairs and cultural programming for much of America. But his fund-raising efforts fell short in a national recession, and he resigned facing a $9 million deficit, about a third of the $26 million budget. Mr. Mankiewicz then became executive vice president of Gray & Co., a public relations and lobbying firm. It was later acquired by Hill & Knowlton, and Mr. Mankiewicz became a vice chairman. He attended Haverford College for a year, but his studies were interrupted by World War II service in the Army infantry in Europe, including combat in the Battle of the Bulge. He graduated from the University of California, Los Angeles, in 1947, earned a master’s degree in journalism from Columbia University in 1948, then worked for newspapers in the Los Angeles area. In 1952, he married Holly Jolley. They had two sons, Joshua and Benjamin, and were divorced. In 1988, he married the novelist Patricia O’Brien. Mrs. O’Brien survives him, as do his older brother, Donald Mankiewicz; his two sons; four stepdaughters, Marianna, Margaret and Maureen Koval and Monica Krider; a 1-year-old granddaughter and eight step-grandchildren. In 1955, he earned a law degree at the University of California, Berkeley, then practiced in Beverly Hills. In 1960, he campaigned for John F. Kennedy, then joined the new administration. Fluent in Spanish, he was director of the Peace Corps in Peru from 1962 to 1964, then directed Peace Corps operations in Latin America.