John D. Ehrlichman, 73, the White House domestic affairs adviser imprisoned for his role in the Watergate scandal, died Feb. 14 at his home in Atlanta. Mr. Ehrlichman's son Tom said his father had diabetes. Mr. Ehrlichman was one of the most prominent members of the administration of Richard M. Nixon. Often scowling from beneath bristling eyebrows, the energetic Mr. Ehrlichman seemed to symbolize, in his pugnacity, the administration's determination to confront its foes and reshape policy over a wide front. He was convicted in the Watergate coverup along with H.R. Haldeman, the White House chief of staff, and John N. Mitchell, the attorney general. In a separate trial, he was convicted for the break-in at the office of the psychiatrist of Daniel Ellsberg, a Vietnam War critic. After serving 18 months in federal prison, Mr. Ehrlichman, a disbarred lawyer, made a new life for himself as an author and appeared to have changed his personality as well. Once known as a brusque stickler for efficiency, he grew a beard and seemed mellow, relaxed and amiable. He suggested that his earlier image might have been distorted. "I was never the person everybody saw in the Watergate hearings," he told an interviewer in 1979. Arguing for a balanced view of the administration in which he was a principal figure, he cited such accomplishments as its passage of significant environmental legislation. Yet the Watergate scandal cast a long shadow on American public life, and it was for his identification with it that Mr. Ehrlichman achieved his greatest prominence. Specifically, he was accused of conspiracy, obstruction of justice and perjury in the matter that started with the June 17, 1972, break-in at Democratic National Committee headquarters in the Watergate office building. Five men with cameras and electronic gear were arrested at 2:30 a.m. in the Democratic Party offices. Watergate, and the high-level efforts to cover it up, forced Nixon's resignation. The term was expanded to include other abuses of power traced to the administration. As the matter unraveled, senior White House officials were implicated not only in covering up the break-in, but also in the use of government agencies in a campaign of "dirty tricks" aimed at discrediting Democratic opponents. In April 1973, Mr. Ehrlichman and Haldeman were summoned to the presidential retreat at Camp David, where Nixon told them they would have to resign. Mr. Ehrlichman, one of those closest to the president, had acknowledged knowing that money was being raised to pay legal fees and expenses of the original defendants, but he insisted that it was a proper act and was not part of any coverup. However, the trial that began in federal court in Washington in 1974 resulted in his conviction. Early in his days at the White House, Mr. Ehrlichman had established an in-house investigative unit and ultimately was instructed to monitor its activities. From this assignment stemmed his conviction for conspiracy in connection with an operation that led to a break-in at the California office of Ellsberg's psychiatrist. In addition to his appearance at his two trials, Mr. Ehrlichman also gained notoriety from his appearance at the Senate's nationally televised hearings looking into Watergate. That did much to cement his public image as a combative and abrasive administration loyalist. Nixon resigned Aug. 9, 1974, as impeachment loomed, and was pardoned by his successor, Gerald R. Ford. Mr. Ehrlichman spent 18 months at Swift Trail Camp, a minimum-security federal facility near Safford, Ariz. He was released on parole in 1978. His son was asked yesterday about reports that Mr. Ehrlichman did not remain a staunch Nixon defender. He answered: "I guess one way to respond to that is: He served his president faithfully. Was the reverse true?" Mr. Ehrlichman was born in Tacoma, Wash., on March 20, 1925, and became an Eagle Scout. During World War II, he was a lead navigator in the 8th Air Force, flying 26 bombing missions over Germany and receiving the Distinguished Flying Cross and other decorations. After the war, he graduated on the GI Bill from the University of California at Los Angeles -- where he met Haldeman -- and in 1951 from Stanford Law School. After his graduation, he became a partner in a Seattle law firm. He had worked in Nixon's 1960 presidential campaign and in his 1962 California gubernatorial race. In the 1968 presidential campaign, he was convention manager and tour manager, traveling across the country arranging campaign events. Part of his reputation for stern punctuality grew from an incident in Lansing, Mich., in which he left two speechwriters behind in phone booths when he ordered the campaign plane to leave for the next event. After Nixon's victory, Mr. Ehrlichman became White House counsel and then domestic adviser. Bobbie Kilberg, a Northern Virginia Republican activist who worked for Mr. Ehrlichman in the White House, praised him as a mentor and a "wonderful" man who "cared about doing in the domestic policy arena what was right and beneficial." He was responsible, she said, for "what was for that time a very progressive . . . Republican agenda." While Nixon concentrated his attention on foreign affairs, Kilberg said, Mr. Ehrlichman, as head of the domestic council, coordinated and shepherded through the government programs aimed at protecting worker pension rights, promoting affirmative action in the work force through the Philadelphia Plan, fostering the sovereignty of Native American tribes and developing revenue sharing and welfare reform. Mr. Ehrlichman also has been credited with important work in establishing the Environmental Protection Agency and in passing clean air and clean water legislation. After his release from prison, he lived first in Santa Fe, N.M., then in Atlanta, where his son said he consulted for a company named Law Environmental. He became a writer and a sketch artist, publishing at least three novels and a memoir, called "Witness to Power: The Nixon Years." He had been spotted earlier as having a way with words and was credited with providing a memorable description of the treatment acting FBI director L. Patrick Gray was to be given at one stage of the Watergate investigation. Gray's nomination to head the FBI on a permanent basis was to be left "twisting slowly, slowly in the wind." In what could be seen as a kind of role reversal, his credentials as a writer led to his being assigned to review, for USA Today, a novel co-written by an editor of the newspaper most identified with Watergate coverage -- The Washington Post. "He savaged it," said the editor, Howard Simons. Mr. Ehrlichman's first marriage ended in divorce, as did his second. Survivors include his third wife, six children and his mother. In 1973, after resigning from the White House and while awaiting possible indictment, Mr. Ehrlichman had three children in college. The family, his son Tom said yesterday, got by with the help of student financial aid. "Thank goodness for financial aid," he said, describing the period as "a time for us all to sort of reinvent ourselves." "Everybody sort of got back to their roots and came through it a better person," he said. In October 1977, before he was granted parole, a taped statement by Mr. Ehrlichman was presented in U.S. District Court in Washington. While in the White House, with the president as his boss, he said, he had "an exaggerated sense of my obligation to do as I was bidden, without exercising independent judgment in the way I might have if it had been an attorney-client relationship." "I went and lied," he said, "and I'm paying the price for that lack of willpower. I, in effect, I abdicated my moral judgments and turned them over to somebody else. "And if I had any advice for my kids, it would be never -- to never, ever defer your moral judgments to anybody. . . . That's something that's very personal. And it's what a man has to hang on to." CAPTION: John D. Ehrlichman looks over pictures taken from video interviews for a documentary on his role in Watergate, "John Ehrlichman -- The Eye of the Storm." ec