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Rumors abound about a politician's sexual dalliances, but his wife stoutly defends him, telling a television interviewer that ``these accusations . . . may, just possibly, be forming a pattern,'' that certain people ``connected to each other . . . are out to destroy [my husband] because he is right about America and they are wrong, and he is good and they are evil. That's what I really think, that it's some sort of plot. ''

Sound familiar? Well, it's not the only thing that sounds familiar in Charles McCarry's Lucky Bastard. In addition to being at the mercy of his libido, the politician in question dodged the draft during the Vietnam War, paid a visit to Moscow during his student years, and when offered a joint to puff on, didn't inhale. He's even involved with a bank that fails.

But he's not William Jefferson Clinton of Hope, Ark. He's John Fitzgerald Adams of Tannery Falls, Ohio. Jack Adams believes he is John F. Kennedy's love child. His mother was a Navy nurse stationed at the hospital in San Francisco where Kennedy went for treatment of his PT-109 wounds. She gave birth to Jack on Sept. 17, 1944, six months after her marriage - she had been mysteriously discharged earlier that year - to one Homer Adams.

Die-hard Clinton supporters will be inclined to dismiss McCarry's book as just another installment in that ``vast right-wing conspiracy'' that Hillary Rodham Clinton has warned us about. The rest of us may find it useful in making some sense out of the last seven months, if not the last six years. Once we get past its central premise, that is.

Jack Adams' story is told by one Dmitri, a KGB operative who is introduced to Jack by one of his Columbia professors, who thinks the young man shows promise as a revolutionary. Dmitri in turn brings Jack to the attention of his superior, Peter, an offspring of Heroes of the Revolution so trusted and admired that he's allowed to run his own operation his own way - and with no official oversight.

It is Peter who fetches Jack to Moscow. ``Peter's contempt for those Americans who loved us was breathless,'' Dmitri explains. ``His idea was to feed this little bird sweets, tie a string to its leg, and then push it out of the nest.''

``The same people who beatified Alger will discover and love Jack - the Jack we are going to design for them,'' Peter said. ``They will invest every kopeck of their moral and political capital in him as soon as they hear him speak in parables. To them, Jack's weaknesses will be strengths, his lies truth, his crimes miracles. ''

It's the parallels with the current political scene that will garner most of the comment about this book, but judged simply on fictional terms, McCarry - a writer of spy novels best known for Shelley's Heart - has notched an impressive achievement. The story is compelling and the characters thoroughly three-dimensional. Jack himself is really engaging, not at all painted entirely in black. He genuinely dotes on his twin sons and displays ``an almost otherworldly kindness'' to the wounded Vietnam vets in a hospital where he works. Among them is his best friend, Danny, a star athlete who undergoes one operation after another and - like Bob Dole - has to learn to write with his left hand.

Jack's wife, Morgan - actually his handler - is almost touching in her single-minded devotion to her anti-capitalist cause. The elusive Peter is an utterly intriguing figure, as is Dmitri.

But what makes the book as significant as it is relevant is its theme, which has to do with lies. The term recurs throughout:

* `` `The fact that he's a born liar doesn't bother you? ' Dmitri asks Peter. `Lies are the truth of the Left,' Peter said, flicking my question off the table like a crumb. `The revolution has always lied about everything for its own reasons. So does Jack for his own reasons. We will make the reasons the same.' ''

* ``Jack was good with audiences because to him a speech was just an elaborately developed lie, with all questions forbidden until the end, when it was too late. He loved to speak and his exhilaration showed, bonding him even more firmly with his audience.''

* ``For many years . . . Jack had been telling true believers to ignore appearances and believe in him as an act of faith. As he explained, `As long as these people think you're lying for a good cause, their cause, you can get away with anything.' ''

* ``That was what Jack was all about. He made liars of us all by recruiting us to defend a faith worth lying for.. . . He stood up for his ideas without really having any ideas. He defended grand concepts and proposed trivial solutions to meaningless problems. He was hailed . . . as a thinker. ''

In the long run, McCarry's novel proves to be not so much about Jack Adams - or Bill Clinton - as about America itself. Lucky Bastard is a political fable and, like all such fables, comes with a moral, summed up in the code phrase by which Jack can recognize Peter's emissaries:

``Welcome to the land of the blind. ''

Frank Wilson is an Inquirer copy editor.