From the author who destroyed John Kerry, a hatchet job on Obama

Jerome Corsi's 'Unfit for Command' helped George Bush win the 2004 election. Now he has written a book about the 2008 Democratic candidate. Obama should be worried, says Rupert Cornwell

It is piled high at the entrance of Washington's leading book stores, with a close-up of the candidate staring from the front cover; pensive and enigmatic – or should that be, sinister and scheming? The book is called The Obama Nation, and this weekend it is set to make a triumphant debut on The New York Times list of non-fiction bestsellers, in the No 1 position. Even more to the point however, Barack Obama is now getting the "Swift Boat" treatment that many say helped doom John Kerry, the Democrats' previous nominee for the Presidency, in 2004.

Four years ago, Jerome Corsi, a former Harvard PhD in political science, leapt to prominence when he co-authored Unfit for Command, in which Vietnam veterans attacked Mr Kerry, suggesting the candidate had lied about his record in the war, and had deliberately sullied the reputation of the US forces who fought in it. Now Corsi is at it again, with The Obama Nation. The title itself, with its deliberate assonance with "abomination", is a giveaway. Any lingering doubts about its contents are banished by the subheading Leftist Politics and the Cult of Personality.

Already 475,000 copies are in print, a vast number even for a controversial book about a fascinating candidate in a fascinating election year. It has become instant fodder and inspiration for America's conservative media, above all the hosts that rule the country's mighty universe of talk show radio. According to The New York Times, Corsi has fed the beast already with 100 separate interviews. The reward for such diligence (backed up with some aggressive bulk marketing) is now spectacularly evident in the bestseller lists.

In essence, the The Obama Nation is a 364-page assemblage of everything unfavourable that has been written about the Democratic candidate, sifted and distilled by Corsi. A selection of chapter headings gives the picture. The first is entitled "Myths from His Father", a play on Mr Obama's 1995 autobiographical memoir, Dreams from My Father. That is followed by "Black Rage, Drugs and a Communist Mentor" and "Kenya, Odinga, Communism and Islam".

Next come chapters devoted to Tony Rezko, the sleazy Chicago operator and briefly an Obama fundraiser, and to Reverend Jeremiah Wright, once Mr Obama's pastor, who preaches black liberation and whom the candidate was forced to disown earlier this year. Finally there is an examination of Obama the national politician, with chapters entitled "The Cult of Personality", "A Far Left Domestic Policy", and "Obama's anti-war, anti-Israel Foreign Policy".

In short, the first African-American with a serious shot at the Presidency is portrayed as a raving ultra-leftist whose patriotism is dubious at best and who has far more links to Islam and militant black politics than he has ever let on.

Corsi naturally insists base partisanship is the last thing on his mind. The book, he claims, is merely to spare the country, "a repeat of the failed extremism that has characterised and plagued Democratic Presidential politics since the late 1960s". He maintains he has never been either a registered Republican or Democrat. "The only political party I ever consciously joined is the Constitution Party," he says. (a primitivist, isolationist and socially conservative party that, among things, wants to abolish income tax, and allow individual states the right to secede).

Corsi denies his opposition to Mr Obama stems from racism, noting that he supported Ken Blackwell, the black candidate in Ohio's 2006 election for governor – which Mr Blackwell lost. It might be noted en passant that Mr Blackwell was an extremely partisan Republican who, as Ohio's secretary of state in the 2004 attracted much criticism from Democrats for his organisation of the presidential vote in the state which, had Mr Kerry won it, would have given him the White House. Nonetheless, shame on anyone who imagines the book is a paean to John McCain, or even Chuck Baldwin, the Constitution Party's candidate for the White House in 2008.

"I am writing this book strictly to examine and oppose Barack Obama," Corsi says. Even so, The Obama Nation smells like a Republican hit job – not least because the chief editor of Threshhold Editions, the subsidiary of Simon and Shuster which has published it, is none other than Mary Matalin, a longtime Republican operative, and recently a senior staffer of the Vice-President Dick Cheney.

Obama supporters would argue that The Obama Nation belongs in the fiction rather than non-fiction category. Several of its accusations have been challenged; others, it is said, are misleading and taken out of context. But no one should claim to be shocked.

Such assault literature has long been a staple of US Presidential campaigns – well before Unfit for Command made headlines in 2004. Bill Clinton and Hillary Clinton have been especially popular targets, to the point of lurid and nonsensical tales of assassination plots and drug smuggling in their home state of Arkansas. With good reason, Hillary complained of a "vast right-wing conspiracy" against her husband and herself. George W Bush, a no less polarising figure, has endured dozens of equally blistering assaults from the left, on everything from his probity and courage to his religious faith and IQ.

Thus far the Obama team has not gone out of its way to attack the Corsi book – probably in the belief that it is mainly preaching to the long-since converted, and thus does not constitute a particular danger. Indeed, its author himself has conceded to The New York Times that his latest opus does not have behind it an organisation like "Swift Boat Veterans for Truth" – a tax-exempt group known as a 527 under American electoral law, that is permitted to indulge in "issue advocacy", unhampered by the financial restrictions imposed on conventional political special interest groups.

In the case of Mr Kerry, of course, the issue was his alleged unfitness to become Commander-in-Chief, on the basis of his purported distortions of his service record in Vietnam, especially as a young officer on a Swift Boat, used for counter-insurgency operations against the Vietcong, and some ancient accusations that some US soldiers in Vietnam had committed war crimes.

Just how seriously the assault damaged his bid for the White House is still a matter for debate. But many argued at the time that the Democratic candidate should have reacted more quickly and more forcefully than he initially did. At the very least, the Swift-Boaters muddied what should have been one of the most clear-cut differences between Mr Kerry and Mr Bush, the former's outstanding combat record in Vietnam, a war which the man who would defeat him famously managed to avoid. In the process a word has been added to America's political lexicon. Be it a small town mayoral election or the struggle for the highest office in the land, no politician today wants to be "swift-boated".

But Mr Obama's advisers nonetheless face a tricky calculation. To come out against the book all guns blazing, would risk drawing attention to its claims. On the other hand, to ignore it, as Mr Kerry first tried to ignore the Swift Boat Veterans for Truth, might simply allow the claims to gain a currency of their own. In politics as in life, refuting a falsehood is far more time-consuming, and difficult, than disseminating one. In other words, mud sticks.

* A man barged into the Arkansas Democratic headquarters yesterday and fatally shot the state party chairman before speeding off in his pickup truck. Bill Gwatney, 48, died four hours later at University Hospital in Little Rock. Police said they did not know the motive of the 51-year-old suspect, who was shot dead after a 30-mile chase.