He's a genius - he says so himself

I have a general view that this is my country. My family helped start it, and we've been in political life of one kind or another since the 1690s." Eugene Luther Gore Vidal is well born, well bred, well read and well said. "I never miss a chance to have sex or appear on television,"

quoth he, neatly glossed by Dennis Altman as the credo of 20th-century celebrity. The first-person full-frontal here is no accident: the ego in question is massive, and always on display. His fancies may be horizontal - he is by his own account a kind of "homosexualist" grand horizontal - but his fantasies are perpendicular. Vidal would be president. He regrets the impossibility of "that golden age, the Vidal Administration". Vidal would also be prophet and sage (and stylist) of the republic of letters. He considers that he has not had his due as a writer. He places himself in the tradition of Henry Adams and Henry James. "Difficult to distinguish between vanity and overweening vanity," as he has reflected in another context. It is only to be expected that he has a lien on posterity. His papers are ready and waiting at Harvard University's Houghton Library.

Altman's book of evidence is neither biography nor autobiography, as he says, but a study deeply indebted to its subject. He has a long personal acquaintance with Vidal and a profound appreciation of his daring writing on sex and gender, confessional and transgressional, The City and the Pillar (1948) and Myra Breckinridge (1968). Altman tries to keep his scholarly distance - he volunteers as if in mitigation that he has been careful to use only material that is in the public record - but he also feels the need to acknowledge Vidal's importance in his life. His stated purpose is "to demonstrate how Vidal 'embodies' a particular critique of American society and politics, and, as part of this, seeks to subvert both the triumphalist view of American history and mainstream assumptions of sex and gender". The inspiration for this project appears to be Gary Wills's John Wayne's America (1997), on which it is patterned, as it were, in counterpoint.

Regrettably, Gore Vidal's America proves to be rather less compelling than John Wayne's. The Altman version lacks the verve and the depth of the Wills version. Altman parcels out a short book into a menu of Vidal's chief preoccupations as a writer: history, politics, sex, celebrity and the like.

He rattles through them without pausing for breath. Inevitably, perhaps, this smacks a little of a cut-and-paste job, but he has his moments. He is especially good on the "aggrieved patriot", saddened and angered at what his country has come to. Altman has little patience with those who stigmatise Vidal as anti-American. "He may not like America but he clearly loves it."

Gore Vidal's America is not hagiography either, and yet it often seems to echo its subject's estimation of himself. Just as Vidal exalts Vidal and slights his competitors ("Whenever a friend succeeds, a little something in me dies"), so Altman tends to do the same. He thinks Vidal "may well be the most significant American writer of the second half of the 20th century", and his greatest contribution the historical series known expansively as the American Chronicles. "Were he to win the Nobel Prize for Literature," Altman offers in a flight of fancy, "it would be for these, just as Churchill did for his four-volume History of the English-Speaking Peoples ."

Other comparators come to mind, but even those entertained here are frequently belittled. Truman Capote, for example, "died in 1984 and is now remembered as a minor literary figure, who built a major social career out of a series of fey gothic writings". (Where is the biopic of Vidal, one wonders, and who would have the nerve to play him?) The comparison with Kurt Vonnegut is said by Altman to be worth exploring, but evidently not by him. James Baldwin makes a few fleeting appearances; Edmund White is barely mentioned, except as an admirer. The obvious contender, Norman Mailer, comes in for cat-fights and (eventual) reconciliation.

Could it be that the self-estimation is an overestimation, and that by setting him so high Altman is merely aiding and abetting? The case still needs to be argued. John Lahr: "No one pisses from quite the height that Vidal does. In his detachment, he is too clear-eyed to hate and too knowing to be grave. His goal, it seems to me, is to teach, which is why he so often writes in epigrams. He doesn't want to be remembered; he wants to be memorised." Lahr speaks truth to glower. Vidal is a tease. Is he Pontifex Maximus , after all, or blogger avant la lettre ?

Alex Danchev is professor of international relations, Nottingham University.