THE BOOK – a personally authored narrative, part life-story, part policy manifesto – is a compulsory campaign tool for any American presidential aspirant these days.

In the past, candidates published real books: worthy academic tomes such as the works of Woodrow Wilson; fiery polemics by the likes of William Jennings Bryan; popular histories, such as John F. Kennedy’s Profiles in Courage. These days the hopeful president’s book is usually as flat and lifeless as the landscape he flies over from one fundraiser to the next; as predictable and cheesy as the smiling photograph of the author on the cover, and much less genuine.

In 2000 George W. Bush published A Charge to Keep, a list of things that, as a compassionate conservative, he would do if he were elected to the White House. It makes odd reading seven years and a couple of wars later; all that talk of healing a nation’s divisions and restoring its international credibility.

The literary output of Barack Obama, the most implausibly possible next president of the United States, is quite different. More than a decade ago, when his presidential aspirations were the thinnest of straws in a Chicago wind, he published Dreams From My Father. It was a bit premature for autobiography – Obama was barely 33 – but it was a rare gem. It documented his heritage – grandson of the Kenyan goatherd, issue of a mixed-race marriage; and the very American life he had built on top of it – first black student president of Harvard Law School, rapidly ascending politician.

The book helped to transform Obama from an exceptionally able young man into a phenomenon. He was no longer a striving lawyer-politician but an avatar of the still unfolding larger American story. In him, the many fabrics of American life seemed to have been woven into something genuinely new and colourful.

The unspoken question the book posed as it hauled in prizes and propelled him to the Senate and then to his oratorical crescendo at the Democratic Convention in 2004, was whether there was anything beyond the phenomenon.

The Illinois senator’s second book, The Audacity of Hope, attempts to answer that question; to channel the exuberant enthusiasm for Obama the Phenomenon into votes for Obama the Candidate.

Sadly, the short and honest verdict is that it fails.

Not because it is dull. It is finely written. It may not be quite up there with Dreams, but by the spirit-sapping standards of most politician’s works it soars. Describing the oratorical style of the veteran West Virginia senator Robert Byrd, Obama writes: “He began to speak, in sombre, measured tones, a hint of the Appalachians like a knotty grain of wood beneath the polished veneer.” You don’t need a ghostwriter when you can construct that kind of English.

The problem is that its diagnosis of America’s ills is not new; nor are any of its prescriptions. Its basic argument is that US democracy has ground to an unproductive halt; that the screaming protagonists on both sides have turned each issue into a casualty-strewn battleground – abortion, gay marriage, guns, Iraq, civil liberties, free markets, race. This has turned off most Americans and failed to advance the “something new” that is needed, Obama says.

His prescriptions aren’t novel. They fit neatly into the left of the political spectrum – he is pro-abortion rights, in favour of more government investment in education; a believer in foreign policy multilateralism. What is new is the way he frames these causes. He grounds them in religious belief, quoting the Bible and trying to reassure religious Americans that Democrats, too, can be God-fearing defenders of good people’s values.

More importantly, he seems genuinely to want to extract the poison from political exchanges. This is best illustrated by his response when a voter complained about a line on his website when he was running for the Senate in 2004. Obama’s site declared that people who opposed the right to abortion were ideologues and extremists. When the reasonable critic complained, he says, he realised that the tone was wrong, contributing only to the degradation of debate. He didn’t change his support for abortion, but he did change the terms he used to express it.

You can’t help but feel, however, that we have been here before. George Bush Sr promised a “kinder, gentler nation”. Bill Clinton was supposed to represent a new politics, a kind of Third Way shared – initially – with Tony Blair.

As Obama glides eloquently through the issues it’s hard to believe that mere words and civility alone will change much; and all too easy to see how the issues themselves – abortion, gay rights, Iraq, globalisation, the environment – are corrosive enough to generate their own partisanship.

All of which takes us back to Obama. His message may not be as new as he would like us to believe. But he is. What Obama knows, under the rhetoric, is that image does matter, and that he himself – black, young, talented, second-generation immigrant, untainted by decades in Washington – is still a better argument for his presidency than anything he promises to do with it.

Canongate, £14.99; 384pp £13.49 (free p&p) 0870 1608080 timesonline.co.uk/booksfirst

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