From a Washington Post obit by Matt Schudel headlined “Ronald Steel, acclaimed historian and Walter Lippmann biographer, does at 92”:

Ronald Steel, a historian and foreign policy expert best-known for his monumental, prizewinning biography of one of the 20th century’s most influential political commentators, Walter Lippmann, and who also wrote a revisionist study of Robert F. Kennedy that took some sheen off the family’s Camelot myth, died May 7 in Washington.

He had a progressive cognitive impairment, but the immediate cause was unknown, said his physician and friend, Michael Newman.