Just who does Barack Obama think he is? As the excitement around his presidential run swells almost to bursting point, so does the number of historical analogies being used to interpret his phenomenon.

Before today’s primary election in New Hampshire, he is being likened to John F. Kennedy, a glamorous optimist who lifted America in 1960 to reach for a higher purpose.

Mr Obama’s campaign privately prefers to liken him to Bobby Kennedy, JFK’s less hawkish younger brother, who 40 years ago briefly symbolised a moral awakening in a divided and traumatised nation.

Hillary Clinton’s advisers whisperingly compare their rival to Jimmy Carter in 1976, who promised a new beginning after Watergate and Vietnam but whose presidency subsequently became a byword for well-meaning incompetence.

Others say that he closely resembles Bill Clinton, who was similarly inexperienced in 1992 when he was first elected on a platform of hope, rather than fear. Were it not for Mr Clinton’s wife being Mr Obama’s chief opponent, they suggest that the former President would scarcely be able to contain himself over the current spectacle.

Nor are the comparisons confined to Democrats. One conservative commentator this week even described Mr Obama as a “liberal version of Ronald Reagan”, whose broad-spectrum appeal ushered in the last significant realignment of American politics.

The answer must be that Mr Obama, with his achingly cool looks, foreign-sounding name and caramel-coloured skin, is perhaps all — and none — of the above. He has chronicled his own struggle with the issue of personal identity, using his first book to peer through an exotic, kaleidoscopic background. He is the son of an absent black Kenyan father and a white mother from Kansas who grew up in Indonesia and Hawaii. In that memoir he describes using marijuana and cocaine — to “push questions of who I was out of my mind” — before travelling to his father’s homeland and getting a grip on his life as a student and then a Chicago community organiser.

This ethnic and cultural hybrid now claims that this life story gives him a perspective that makes him unique among presidential candidates, past and present. He hopes to move America beyond the social ructions of the 1960s and away from a foreign policy built by leaders who do not understand what it is like to be on the receiving end of US power.

Mr Obama suggests that the victims of Darfur, gazing up at a helicopter containing fact-finding senators, will feel hatred rather than gratitude. His supporters believe that the election of a president such as him will single-handedly transform the attitude of a Muslim student sitting in a madrassa in Pakistan.

Not so long ago he was being told to forget about seeking high office because of that same background. Conservative-leaning America, he was told, would not touch a black man with a first name that rhymed with Iraq and a second that was uncomfortably close to “Osama” — not to mention his middle name, Hussein.

He has consistently risen above such doubts, often quoting Abraham Lincoln as he appeals to the “better angels in our nature”. Little more than three years have elapsed since he was a virtual unknown, not yet elected to the US Senate, who burst into national prominence with a now-legendary speech at the 2004 Democratic convention. “There is not a black America and white America and Latino America and Asian America,” he declared, “there’s the United States of America!”

He returned to this theme after winning the Iowa caucuses on Thursday night with overwhelming support from white voters. “They said,” his booming baritone paused, “this day” — another pause — “would never come”. Ecstatic applause exploded across the hall as he continued: “They said our sights were set too high. They said this country was too divided; too disillusioned to ever come together around a common purpose. But on this January night — at this defining moment in history — you have done what the cynics said we couldn’t do . . . you came together as Democrats, Republicans and independents to stand up and say that we are one nation, we are one people, and our time for change has come.”

Times Recommends

• Times Charity Appeal: SolarAid
• Is it Black Monday all over again for Dubai?
• Behind the scenes at the biggest deal