Leonard Garment, a high-powered lawyer and adviser to President Richard M. Nixon, died at 89. (Photo by Frank Johnston/The Washington Post)

Leonard Garment, a top-shelf Washington lawyer whose most famous client was the embattled president of the United States, Richard M. Nixon, at the peak of the Watergate scandal, died July 13 in New York City. He was 89.

His daughter, Ann Garment, confirmed his death but did not cite a specific cause.

For decades, Mr. Garment was one of the most prized lawyers on the East Coast. His roster of clients included former attorney general Edwin Meese III, former national security adviser Robert C. McFarlane, Toshiba, and the jazz bandleader Benny Goodman.

The latter client reflected Mr. Garment’s early life as a professional saxophonist and clarinetist. As a young man, he performed in the Woody Herman big band and with future Federal Reserve chairman Alan Greenspan.

By the end of his career, Mr. Garment was seemingly omnipresent in elite Washington circles. But in his first and most enduringly important assignments here — as special consultant and later counsel to Nixon — he almost seemed out of place.

For starters, Mr. Garment was a Democrat in a Republican administration. The son of Jews from Eastern Europe, he found himself working for a president who was prone to spewing anti-Semitic vitriol. At one time in his life, Mr. Garment wrote, he had been a “reflexive Nixon denigrator.”

Mr. Garment met the former vice president in the mid-1960s at the high-powered New York law firm that would bear Nixon’s name as Nixon, Mudge, Rose, Guthrie, Alexander and Mitchell.

At the time, Nixon was battling political irrelevance after his defeats in the 1960 presidential campaign and the 1962 California governor’s race. Months before joining the firm, he had convened what he called his “last press conference” and told reporters they wouldn’t “have Nixon to kick around anymore.”

Mr. Garment, for his part, was battling boredom. “I couldn’t have cared less that Richard Nixon was the political Antichrist of eastern liberalism,” he wrote in a highly regarded memoir, “Crazy Rhythm: From Brooklyn and Jazz to Nixon’s White House, Watergate, and Beyond” (1997).

Nixon, Mr. Garment wrote, was “an opening to a different life and the possibility of salvation.”

In the run-up to the 1968 presidential election, he helped assemble the campaign team that would help fill out the ranks of Nixon’s administration. After Nixon’s election, Mr. Garment was named special consultant, a role that relegated him to laboring mainly in what he called “the distant swamplands of Republican politics.” His portfolio included issues such as desegregation and affirmative action, American Indian concerns and the humanities, as well as acting as a liaison to American Jews.

His direct dealings with the president, he wrote, were “virtually nonexistent.” In hindsight, such distance worked to his advantage.

Mr. Garment became legal counsel in 1973, after Nixon fired John W. Dean III, who had begun cooperating with Watergate investigators. Mr. Garment was, he noted, “the last senior White House staffer who (a) had a license to practice law and (b) was not a potential indictee.”

On Nixon’s urging, he asked then-attorney general Elliot Richardson to fire Watergate special prosecutor Archibald Cox. Richardson resigned rather than comply, leading to the chain of resignations that became known as the Saturday Night Massacre.

Mr. Garment was credited with encouraging Nixon not to destroy White House tape recordings, an act that he said would have been obstruction of justice. Mr. Garment later said that the advice was sound legal judgment but poor political advice.

By late 1973, he had encouraged the president to resign, as Nixon would ultimately do on Aug. 9, 1974. In the last days of the presidency, he spoke little with Nixon, save for one conversation the night before the resignation.

“I’m sorry I let you down, Len,” the president said. He hung up before Mr. Garment could respond.

Leonard Garment was born May 11, 1924, in Brooklyn. His mother was from Poland; his father came from Lithuania and made dresses for a living.

In his memoir, Mr. Garment described his childhood as an unhappy time. Music became his outlet. He funded his education in part by playing clarinet and saxophone in jazz groups, and he graduated from Brooklyn College and Brooklyn Law School, where he was first in his class.

In 1957, he made partner at the New York law firm where he would meet Nixon. Mr. Garment described himself as “one of a handful of Jews in my generation who squeezed through the keyhole of the tightly closed Gentile fraternity of Wall Street lawyers.”

Mr. Garment emerged from the Nixon administration with his reputation undamaged — a product, perhaps, of his distance from the president. Mr. Garment was an adviser to President Gerald R. Ford, who later named him U.S. representative to the United Nations Human Rights Commission.

He later returned to legal practice in Washington and New York. He prominently assisted his friend Robert H. Bork, a former Nixon colleague who had finally fired Cox, in his unsuccessful nomination for the U.S. Supreme Court in 1987.

Mr. Garment struggled with depression, as did his first wife, the former Grace Albert, whose death in 1976 was ruled a suicide. Their daughter, Sara Garment, died in 2011, and their son, Paul Garment, died in 2012.

Survivors include his wife of 33 years, the former Suzanne Bloom, of New York City; their daughter, Ann Garment, also of New York; a brother; and a grandson.

In addition to his memoir, he wrote “In Search of Deep Throat” (2000), in which he inaccurately guessed that Deep Throat, the enigmatic source at the center of The Washington Post’s Watergate coverage, was Nixon aide John P. Sears. In 2005, W. Mark Felt, a top FBI official, was revealed as the true Deep Throat.

At one time, Mr. Garment had been suspected as the secret source, an allegation he had always denied. Until the end of his life, he remained devoted to the president he had served.

“Placed on the fringe of Nixon’s life,” he wrote, “I was exposed mainly to his attractive sides — his intelligence, idealism, and generosity. Only by ‘hearsay,’ mainly tape-recorded, did I ‘see’ the fulminating stranger I was happy not to know.”