It's shaping up to be the literary event of the year thus far. On Tuesday, Simon & Schuster will publish O: A Presidential Novel, and the intrigue isn't just confined to a controversial plot featuring Barack Obama standing for re-election. The identity of its writer has also been kept under wraps, with the publishers content to say that it was written by someone "who has spent years observing politics and the fraught relationship between public image and self-regard".
So why the secrecy? The author is also said to have vast personal experience of working at the White House: he "has been in the room with Barack Obama" - and therefore wishes to remain anonymous.
Which, naturally, hasn't prevented wild speculation regarding the book's provenance. Everyone who has recently left the White House has been linked with O - from the former press secretary Robert Gibbs to the top Obama adviser David Axelrod, who is off to run the re-election campaign. Dedicated watchers of American political literature suggested the involvement of Joe Klein - the Time reporter who was eventually exposed as the anonymous author of the Bill Clinton novel Primary Colors (later a film starring John Travolta). However, Klein immediately distanced himself from the book. "You get to do that only once a lifetime," he told the website The Daily Beast.
Still, the lives of US presidents have certainly proved to be fertile source material for novelists - and not just anonymous ones. One might expect sensational takes on the commander-in-chief from debut authors desperate for the oxygen of publicity, but some of the modern age's most celebrated writers have been seduced by the internal struggles of these famous men.
Indeed, Philip Roth has had a go twice - taking on Franklin Roosevelt (The Plot Against America) and Richard Nixon (Our Gang). The former refashioned history, with Roosevelt losing the 1940 presidential election, while the latter was a savage political satire - with a barely disguised character called Trick E Dixon.
Nixon would also go on to feature in Thomas Pynchon's postmodern masterpiece Gravity's Rainbow and the last of James Ellroy's Underworld USA trilogy, Blood's a Rover.
Perhaps such big literary names feel entitled to expand their palettes to presidents: Gore Vidal mentions most of the incumbents from McKinley to Truman in his Narratives of Empire series, while Don DeLillo's Libra was an enthralling take on John Kennedy's assassination. So is it the charisma, the (in some cases) notoriety or the celebrity status of most American presidents that makes them ripe for fiction?
One author who should know is Jed Mercurio, whose third novel, American Adulterer - in which said adulterer is none other than John F Kennedy - came out in 2009. Can he understand the interest in presidents - from writers and readers alike?
"Certainly, because American presidents are global figures in a way that few other heads of state are," he says. "And American politics is personality-based, so presidents' personal styles and histories are widely enough known for the novelist to explore."
But colourful personal histories are surely just the beginning of a process. A convincing narrative still has to be fashioned. Looking back now, is Mercurio happy that he took on JFK?
"Oh yes. What I would say is that when you write about a famous figure, some readers approach the book as if it's a biography. They're coloured by their own personal prejudices about the protagonist. In my case, I think the tone of the novel suggests the rules of engagement regarding the truth. A realistic work requires verisimilitude but a surreal one doesn't."
And American Adulterer does have a surreal edge, thanks to its clinically hypnotic prose, depicting an idealised version of a Kennedy who is as virtuous as possible in every aspect of his life apart from his philandering. At the time, Mercurio was very clear that the idea - a character study of a person who was in the grip of a secret - came well before the famous man he chose as a protagonist. So is that the advice he would give to any author considering a novel based on a president: to know the story rather than the history?
"Well, I wouldn't give advice to anyone," he laughs. "It remains to be seen if the strategy around O, with its anonymous author and so on, works. I'd say it's only a mistake if choosing a conspicuous protagonist turns an otherwise good book into a bad one."
It's telling that, in the month that O is published, The Kennedys - a multimillion dollar television mini-series - has been axed by American television networks. It appears, then, that the printed page is still the natural home for fictionalised presidents. We'll just have to wait and see whether O can live up to such a grand tradition.