Political family ... young Mitt Romney with his father, George. Photo: Grey Villet

'Accomplishing real change is not something I just talk about, it is something I have done,'' Mitt Romney said on Friday morning in Wisconsin during one of what he calls his ''closing argument'' speeches.

It is true. Mitt Romney's greatest political asset is his endless, audacious capacity for change, though this is probably not what he was getting at in Wisconsin.

The pro-choice healthcare reformer who won the governorship of the liberal state of Massachusetts is not the ''severe'' conservative who, in announcing his candidacy for the 2008 presidential election, said: ''I believe in the sanctity of human life, I believe that people and their elected representatives should make the laws, not unelected judges.''

The fiscal hawk who appointed Paul Ryan as his running mate after beating down a posse of far-right nomination contenders during this year's primary race is not the same candidate who left Barack Obama flat-footed and blinking in his wake as he preached moderation in the first presidential debate in October.

Romney's critics constantly attack his easy movement across a landscape of other people's entrenched positions as evidence of opportunism, at best, dishonesty at worst. Obama calls it Romnesia.

Even some of the candidate's supporters fret about it.

In the recent PBS documentary about the two contenders, the New York Times commentator David Brooks confesses to finding Romney's ideological elasticity ''disquieting''.

Perhaps they are missing the point. After four years of a presidency elected on the promise of transformation that has instead delivered bitter governmental logjam, and in the face of snowballing debt and deficit that will only grow as the government meets its health and welfare obligations, many Americans appear exhausted by the very notion of big ideas that are firmly held.

Many, it seems, are drawn to a clinical bookkeeper, someone like Romney the business consultant, who can parachute in to clean out the mess unfettered by … well, by belief.

Some who have written endorsements for Romney in the past week, such as The Daily Beast's David Frum as well as Brooks in The New York Times, have done so stating it is because they do not believe he will do what he has promised to do.

Romney's personal life is as famously steady and stable as his politics are mercurial. At the beginning of each of his debates, Romney has said, he strides out to the stage, catches his wife Ann's eye, then writes his father's name at the top of his pad of note paper: George Romney.

The Romney family has always been prominent in the Church of Jesus Christ of Latter-day Saints. George was born in Mexico in a Mormon colony established by refugees from US government persecution.

The Mexican revolution forced further flight, and the Romneys moved to California, then back to Utah. By then, the Mormons had shed polygamy and the American repression had ended.

By the time Mitt was born, George's dazzling career was well under way. He established himself as a star chief executive of American Motors Corporation, then a moderate Republican governor of Michigan and then a contender in the 1968 presidential campaign, before serving in Richard Nixon's cabinet as secretary for housing and urban development.

Mitt was an unremarkable student and unexceptional athlete at his elite school, Cranbrook. He was known as an enthusiastic joiner, an engine of school spirit and the architect of occasionally cruel pranks.

George's presidential bid came unstuck in the primaries while Mitt was in France completing his church-mandated mission. George was a man of firmly held views. He was a civil rights advocate and had battled his party's lurch to the right under Barry Goldwater. Though he had at first supported the US engagement in Vietnam, he came to oppose it after a visit to the country in 1967.

He could not have explained his change of position more poorly. In an interview he said while in Vietnam he had experienced ''the greatest brainwashing''. His candidacy was over and Mitt, who had been following it from France via newspaper clippings, was devastated.

Mitt's sister, Jane, told the authors of the biography The Real Romney, Michael Kranish and Scott Helman, ''Mitt is naturally a diplomat but I think that made him more so. He's not going to put himself out on a limb. He's more cautious, more scripted.''

Having already graduated from Stanford, where he had protested against the anti-Vietnam protesters, Mitt moved on to Harvard business school, a common path for Mormons, for whom success in business and politics is encouraged.

There he stumbled into a revolution in American business. Students were learning that the traditional corporate model rewarded slow-moving executives who were blinkered to real opportunity. The consultant was being invented, the notion of the clear-eyed expert who could march in, solve problems, massively increase profits and move on.

The model captivated Romney and on graduation he was hired by one of its new champions, Bill Bain. Romney proved to be very good at consulting. He could take in massive amounts of information, digest it and act on it with extraordinary focus. After a while it dawned on Bain that as consultants they were making a lot of money for other people.

Why not buy the dud companies and make the money themselves? Bain Capital was created with Romney at the helm.

According to The Real Romney, during his 15 years with Bain, the firm invested about $US260 million in its top 10 deals, reaping a return of almost $US3 billion. The authors estimate that in one deal alone Romney may have secured $US40 million personally. It has been reported he ruthlessly exploited regulatory loopholes while scrupulously avoiding business with the manufacturers of guns, booze and tobacco.

Romney's leadership qualities had already been recognised by his church, where he had been appointed a bishop, devoting up to 30 hours a week giving spiritual and personal guidance - and indeed direction - to the congregation he had been selected from.

Faithfully following in George's footsteps, in 1994 Romney turned his attention to politics, deciding to challenge Senator Ted Kennedy, a hero in the Democrat heartland of Massachusetts, casting himself as a socially liberal economic conservative. But reports filtered into the media that in private and before Mormon audiences he had labelled homosexuality ''perverse'' and counselled women against abortion.

Romney underestimated Kennedy's political instincts and ruthlessness.

The old senator launched a vicious advertising campaign portraying Romney as a vulture capitalist, carving up companies, laying off workers for profit - the model for Obama's first strike over the northern summer.

And he delivered a barb so devastating it was replayed and cheered during this year's Democratic convention: ''I am pro-choice. My opponent is multiple choice.''

By the time Romney became the governor of Massachusetts in 2002 he had already established himself on the national stage with his rescue of the Salt Lake City Winter Olympic Games from its fog of corruption, and the family had weathered Ann's multiple sclerosis diagnosis.

Romney had won office in an overwhelmingly Democratic state, and spent much of his time issuing vetoes that were overturned. If he was going to use the office as a springboard into national politics, he needed a bigger project. Weirdly, this turned out to be healthcare reform.

The conservative Heritage Foundation had published a paper suggesting if each citizen were required to take responsibility for their own healthcare the overall costs would drop. Romney seized on the idea, which became known as the ''individual mandate''.

He and his old enemy Ted Kennedy worked together on the Massachusetts reform, which eventually became the model for Obamacare. It has been hailed as a great success.

With his signal achievement bedded down, Romney quit the governor's mansion only to lose the Republican presidential nomination in 2008 to the war hero John McCain, who in turn lost the White House to Obama. But Romney's campaign for 2008 never stopped; he just recalibrated his sights to 2012.

It is hard to imagine the frustration Romney must have felt in the first two years of the Obama presidency, when the Republican Party turned so savagely on Obamacare. He realised when the time came to return to the stump he would not even be able to campaign on his time as governor, let alone his great reform.

Instead he followed the posse to the right, boasting of his remarkable achievements in the private sector, promising massive cuts in all spending but defence, railing against illegal immigration.

By demolishing his opponents in an avalanche of negative advertising and sticking trenchantly to the right, Romney won the Republican nomination. And he stayed on the right until that first debate early last month when moderate Mitt emerged from his cocoon, beat his wings and blew Obama off the stage.

Nick O'Malley is the US correspondent.