Elizabeth Warren is special

The idea that political rights and duties derive from a tacit social contract which permits this kind of argument has a history tracing back to antiquity, but it flourished during the seventeenth century, when philosophers as varied as Hobbes, Locke and Rousseau put forward their non-theological accounts of the foundations of political authority. The mid-twentieth century saw a major revival, largely due to the late John Rawls' 'veil of ignorance', a device for making judgments of fairness in what seems a uniquely rational way - one which also meshes with both the 'golden rule' of Christianity and Kant's concern for reciprocity.

Warren's response emphasises the degree to which incomes and taxes - and the pattern of wealth distribution they display - are contingent on the co-operation of those on lesser incomes - be they teachers, firemen, road workers, police, carpenters, bus drivers, nurses, bank clerks or aged carers, in a common enterprise. It means the property rights of the wealthy are determined not just by the effort and talent they contribute, but as part of a comprehensive scheme of fairness whose component parts, depending on the evidence, are always subject to a better, more realistic interpretation.

Warren argues from this evidence; in a first book, co-authored with daughter Amelia Tyagi, she found that a fully employed worker earns considerably less than thirty years ago. Although modern families spend less on clothing, appliances, and consumption, core expenses such as mortgages, transportation, health and child care have increased dramatically. (The Two-Income Trap: Why Middle-Class Mothers and Fathers Are Going Broke. Basic Books, 2003). Jeff Madrick, writing in The New York Times, commented:

The authors find that it is not the free-spending young or the incapacitated elderly who are declaring bankruptcy so much as families with children ... their main thesis is undeniable…. More clearly than anyone else, I think, Ms. Warren and Ms. Tyagi have shown how little attention the nation and our government have paid to the way Americans really live.

In the two years since her election as Senator - the most dramatic contest in Massachusetts history because the odds were so much against her - Warren has been a forceful and articulate contributor to national debates. But her rapid rise to household name status has more to do with public interviews and TV question-and-answer sessions, many of which have gone viral, including those with heavyweights Ben Bernanke, former Federal Reserve Chairman and Tim Geithner, former Treasury Secretary.

A good example of her style is a clash with CNBC anchors, who seemed to forget she was a leading authority and tried to bully her; but others highlight her forthright manner and forensic skills in Senate hearings on regulatory failures behind the 2008 financial melt-down, and hearings on systemic failures behind the US- based Hongkong and Shanghai Banking Corporation, which money-laundered billions for Mexican drug cartels. These are dramatic and often entertaining videos, because the explanations are implausible or the silences and body language revealing; there is a good selection on YouTube.

American media culture thrives on icons, precursors and clichés and lazy or unimaginative journalists have begun to portray the Senator as a female version of James Stewart's character in Frank Capra's 1939 film Mr. Smith goes to Washington, the story of a naïve and idealistic man whose basic decency triumphs in a world of deception and intrigue.

But Warren is in a class of her own - she has spent much of her life studying economic theory and regulatory systems, and believes theory must square with practice, and practice with the nation's values. She has also acquired - through a long and at times brutal apprenticeship - a good understanding of how Washington works.

She is also fighting for a good deal more than a national camp for the Boy Rangers of America. She wants nothing less than the nation to live up to its image of itself as home of the brave and land of the free. She wants America to fulfil its destiny as a nation which treats all its citizens as members of the same community, regardless of their ability to compete for wealth, social status or political power. She wants, in short, to bring new life to Obama's early and inspiring, but now fading, vision.