Pity poor John Kerry. Just when Americans should be focusing on him and what he has to offer as the presumptive Democratic presidential candidate, along comes Bill Clinton with his memoir. Suddenly Kerry faces the specter of the former president dominating the talk shows serving up titillating details about Gennifer Flowers and Monica Lewinsky. And all at once it's "John Who?"

Well, not really. If the past is any guide, Kerry can relax, because Clinton's memoirs are likely to be as absorbing as watching the House pass a resolution establishing National Memoir Week.

The history of presidential memoir writing is, in sum, a history of failure. For the most part, presidential memoirs offer little in the way of insight into or understanding of the men who have held the nation's highest office. They're mostly written to celebrate a president's triumphs while excusing his failures. Only one really manages to rise above the banal to open a real window onto a leader's soul and qualify as a genuine literary achievement. As for the rest, when they're not self-serving, they're shallow, dull and lined with boilerplate.

Even Ronald Reagan, the Great Communicator, was less than great when it came to writing his own story. Americans looking, in the wake of his death, for a key to his personality, an explanation of his vision and an understanding of his legacy won't find much of any of that in "Ronald Reagan: An American Life," published in 1990. The book is undeniably readable; the chapters are short and filled with homespun tales. But the story of Reagan's presidency is somewhat sanitized: The controversial Iran-contra affair that marred his second term is glossed over, and Congress gets the blame for the enormous deficits of the time. And Reagan's self-deprecating humor and modest, self-effacing demeanor are mostly missing from the writing. Like so many presidential memoirs, it reads like what it is -- a volume meant to recount triumphs, carefully penned with the help of a ghostwriter. Harper's editor Lewis Lapham said it best: Reagan not only didn't write his memoir, "he probably didn't read it."

James Buchanan, the first president to write his memoirs, could have used a ghostwriter. Published in 1866, the book is as forgettable as his presidency. It sold poorly, although the case could be made that in the months after the Civil War ended, Americans were intent on forgetting the crises of the past. But "Mr. Buchanan's Administration on the Eve of the Rebellion" didn't help itself -- it is ponderous, defensive and, worst of all, apologetic. Buchanan's poor reputation -- as an indecisive leader at a time when the country was headed for a split -- has been recently rehabilitated by historians, who argue that he was simply trying to steer the nation clear of conflict. But the reading public of Buchanan's day was unforgiving.

Herbert Hoover had a similar problem. Though he was a man of enormous goodwill, the 31st president was blamed for the Great Depression -- or, at least, for not doing enough to ameliorate its consequences. His post-presidential career did not enhance his reputation: He opposed the New Deal and argued against American intervention in World War II. The result was predictable: When "The Memoirs of Herbert Hoover" appeared in 1951, few seemed to care. The work was an off-putting three volumes, the last of which contained charts and numbers (including balance sheets on world food statistics) and offered a detailed analysis of the failures of Franklin D. Roosevelt's administration -- which had, of course, lifted the nation out of the Depression. The book sank like a stone.

Buchanan and Hoover were typical of many presidents in the first 150 years of the republic who decided to write memoirs. For the most part, failed ones needed to explain their actions; successful ones didn't. George Washington retired to Mount Vernon and kept silent, Thomas Jefferson returned to Monticello and wrote letters, and Andrew Jackson went home to the Hermitage, where he struggled to pay his son's debts. The one exception to this early rule was Teddy Roosevelt. An explorer, naturalist, politician, soldier and writer, Roosevelt was a strong president and an unforgettable man. But he, too, wrote a forgettable memoir.

"Theodore Roosevelt: An Autobiography" lacks the man's vibrancy and reads like a series of predictable moralisms devoid of the biting insights that characterized his public pronouncements. It didn't do well and failed to impress the critics. It still fails to impress, largely because it doesn't measure up to his other offerings. Roosevelt was a prodigious and talented writer, whose works on naturalism ("The Winning of the West") and the Spanish-American War ("The Rough Riders") are lively and compelling in precisely the way his autobiography isn't.

It wasn't until Harry Truman that the idea that only failed presidents needed to write memoirs, to explain their failures, was fully laid to rest. Truman, surely a successful president, was intent on providing some judicious insights into his own time. (He also needed the money.) Nevertheless, the resulting two volumes of "Memoirs of Harry S. Truman: Years of Trial and Hope," lack the toughness Truman brought to his presidency. Harry didn't "give 'em hell" (and his poorly selling memoirs didn't make him rich).

The same can be said of Lyndon Johnson's "The Vantage Point: Perspectives of the Presidency, 1963-1969." The man whom historian Doris Kearns Goodwin called "perhaps the greatest storyteller of his age" simply could not reach out to an audience through the written word. It showed in his memoirs, which are dull, labored and superficial.

No one disappointed more than Richard Nixon, whose "RN: The Memoirs of Richard Nixon" was viewed as his last chance to tell the truth about Watergate. It was not that Nixon failed to be Nixon: It was that he succeeded. "RN," first published in 1978, is a dissembling work in which the president attempted to deflect criticism from himself by blaming others for Watergate and fumed endlessly over his loss in 1960, which was apparently still eating at him. And the book was a major publishing letdown: It sold 262,000 copies, when the publisher had hoped it would sell millions.

Gerald Ford (helped along by ghostwriters) and Jimmy Carter (who vows that he wrote every word of his book himself) likewise penned ultimately unsatisfying accounts of their presidencies. The prose of "A Time to Heal: The Autobiography of Gerald R. Ford" flows effortlessly along, but the book is nothing more than a laundry list of events and Ford's reactions to them. Jimmy Carter's personal beliefs, on the other hand, come through clearly in "Keeping Faith: Memoirs of a President," though the last pages of the book, describing the all-important final days of his presidency (the Iran hostage crisis and his loss to Reagan) seem hurried. In truth, "Keeping Faith" is not nearly as good as Carter's affecting memoir of growing up in Georgia, "An Hour Before Daylight: Memories of a Rural Boyhood."

We shouldn't be too disappointed by these judgments: Presidents are politicians, after all, not memoirists. Even so, there is one notable exception amid the field of mediocrities -- the most popular and widely read memoir by a president, written by Ulysses S. Grant.

When he published Grant's "Memoirs" in 1885, Mark Twain, who was astonished at the sophistication of the writing, compared it to Caesar's "Commentaries." Grant's book is a stunning piece of literature, made all the better by the fact that he wisely focused his attention on the Civil War and not on his presidency. Written in 13 months, the work is entirely Grant's own. And Grant did not write either to retrieve his reputation or to gain public office, but, like Truman, to stave off bankruptcy. But where Truman failed, Grant succeeded. With Twain urging him on, he struggled through the pain and exhaustion of his battle with throat cancer to finish the work; he did so just days before his death.

Reading the book is a mesmerizing and uplifting experience. Certainly I found it so when I first read it nearly 20 years ago. While it's long, the writing is spare and straightforward; the greater the military crisis, it seems, the greater Grant's restraint. He admits his fears without embarrassment. The result is a fast-paced, unaffected story that is, in the words of the critic Edmund Wilson, "a unique expression of the national character." In a life full of heroic moments, Grant's struggle to finish his memoirs might have been his greatest. His wife, Julia, reaped the benefits -- collecting more than $450,000 in royalties, an enormous sum at that time. No other president has ever penned a book that matches the power of Grant's "Memoirs."

Will Bill Clinton break the mold? He could if he wanted to. Unlike Buchanan or Johnson, he could write a memoir that is neither an apology nor an explanation. Unlike Nixon, he has no good reason to dissemble; like Grant, he has nothing to lose by being blunt. Being open would no doubt be painful. But like Grant, Clinton could overcome the pain and provide America's readers with a window onto his own struggles. Over the last year, he's had the chance -- and the guarantee of around $10 million -- to confess his fears and mistakes as well as relate his triumphs, to write a book that would be unique and welcome.

Do I think Clinton's "My Life" will be that kind of book? I could always be surprised, I suppose. But looking at history, I'd be inclined to say that John Kerry really has nothing to worry about.

Author's e-mail:

mperry@jwidc.com

Mark Perry is a vice president of Jefferson Waterman International, a Washington lobbying firm, and the author of "Grant and Twain: The Story of a Friendship That Changed America" (Random House).