Edward Klein is a prolific writer, and what a supremely confident one.

The author of three bestsellers about the Kennedys, and a former editor at the New York Times and Newsweek, Klein was casting about for a new book project even as he was striking a deal for an account of Jackie Kennedy Onassis's final days, writing magazine profiles and penning a weekly column.

"It struck me that Hillary Clinton had replaced any Kennedy," he said in an interview yesterday. "There was no woman or man who is of greater interest." Of course, he knew that close to two dozen books and tens of thousands of pages already had been written about the former first lady and current junior senator from New York, including her own best-selling autobiography. "But I spent a little time digging," he said, and that convinced him he could contribute something new.

His book, "The Truth About Hillary: What She Knew, When She Knew It, and How Far She'll Go to Become President" -- his fifth book in nine years -- goes on sale today. The bold assertiveness of the title, along with advance word from the publisher that Klein's "shocking new accounts" would do to a potential Clinton presidential run what the Swift Boat Veterans for Truth did to John Kerry, seems to have made many a Hillary-hating heart beat faster. Orders for the embargoed book caused Sentinel, the conservative imprint of Penguin, to print 350,000 copies, said Sentinel's associate publisher Will Weisser.

"This is a book full of blatant and vicious fabrications contrived by someone who writes trash for cash," Philippe Reines, Clinton's press secretary, said yesterday.

But the 305-page book relies so heavily on previously reported information about Clinton -- sometimes the author repeats rumors and then footnotes them to a prior author who referenced the rumors -- that new, corroborated news seems slight.

One of Klein's major contentions is that Hillary Clinton knew about Monica Lewinsky's relationship with her husband more than two years before their relationship became public, but Klein doesn't have the goods. Instead, he relies on one anonymous Democratic National Committee staffer, who herself doesn't seem to have firsthand or even secondhand information.

An on-the-record anecdote about the young Hillary bloodying the nose of a boy in her fifth-grade class for giving away one of her baby rabbits becomes, to Klein's thinking, evidence of a "controlling, combative" personality that rules Clinton's personal and political behavior to this day.

Pre-publication hype -- and its follow-up, pre-publication counterattack -- made it seem that Klein had uncovered an amazing compendium of new allegations about a woman and her husband, about whom one might have thought the most fantastical things already had been alleged. Matt Drudge trumpeted exclusive sneak peeks at sordid material. People mentioned in a leak to a London tabloid popped up in the New York Post to lambaste Klein's techniques. Vanity Fair, where Klein is a contributing editor, printed an excerpt about Clinton's Senate campaign. Media Matters for America, a journalism watchdog group headed by David Brock, who penned his own critical Hillary Clinton book before undergoing a conversion, pointed out factual errors in the magazine piece paragraph by paragraph.

Some conservatives touted the book in e-mails and blogs, but others have denounced some of the more sensational claims. The controversy apparently frightened off producers for the television morning shows, although Sentinel's Weisser said Klein would make the rounds of some TV talk shows, including Fox's "Hannity & Colmes." Bill O'Reilly, who hosts the No. 1-rated cable news program, said he would not invite Klein to appear, because he also had refused to interview author Kitty Kelley for what he called her "personal attacks" in her book about the Bushes.

Klein said yesterday he never has been an ideologue. He spent more than a decade at Newsweek, where he wrote cover stories on Vietnam and the India-Pakistan and Mideast wars before becoming assistant managing editor. He moved on to become executive editor of the New York Times magazine, where he spent 11 years before he was pushed out when the paper's top editor changed. In those years, he didn't vote.

After leaving the Times, he got married for the third time and began writing for Parade and Vanity Fair. (One of his sons, Alec, is a reporter for The Washington Post.) Since 1991, he has been the author of Walter Scott's Personality Parade in Parade, which is inserted into 37 million Sunday newspapers across the country. That job, which pays about $300,000 a year, and his bestsellers have made him far wealthier at 68 than his years as an editor did.

"I certainly didn't go into this with a political agenda, at first," said Klein yesterday about "The Truth About Hillary." His research and manuscript have not been directed by conservatives, he said, and his conclusions are his own.

Asked whether he objected to his work being compared to "Unfit for Command," the book by Swift boat veterans that challenged Kerry's own account of his war service, Klein said, "Insofar as the Swift boat veterans were attempting to shed light on John Kerry's character, if I am being compared to them that way, I have no problems with it."

Edward Klein's book relies heavily on old accounts.