For all our sophistication, we still instinctively trust our leaders

It is not so much the sex and the lies that matter, but the videotape - the way the lie is conveyed to us

HERE IS what is puzzling me. I assumed from the start that Bill Clinton was lying about his relationships with Gennifer Flowers and Paula Jones and that he had indeed had been more than office buddies with "that woman". But the moment when the lie becomes flesh, when we feel the full impact of the blow to our trust, still jolts.

All the ready cynicism about politicians can not expel an idealism which is the life-blood of democracy: a desire to believe that the universal franchise will produce an honourable person at the top.

The relationship between modern electorates and their leaders is thus a weird cocktail of stubborn belief in their probity, combined with a ready acceptance that they will sometimes behave in a way we would not find to be trustworthy if we knew the details. It is not so much the sex and lies that matters, but the videotape - the way that the lie is conveyed to us which defines whether that magic trust factor remains intact or not.

A politician who forfeits this link of trust can rarely regain it. A reputation for untrustworthiness, as Richard Nixon discovered, eclipses all other achievements; and A J P Taylor's comment on Lloyd George - "He arouses every feeling except trust" - still blots the memory of the great radical reformer.

Traditionally, trustworthiness is taken to mean that the person who inspires it behaves with consistency and that this consistency is something positive. Hence the public's obsessional belief that those they elect should keep their promises, and the lengths politicians go to make promises - now recast in quasi-religious language as "pledges" - which they can at least be seen to keep, even if we all know that the essence has gone unfulfilled.

Yet President Clinton was perfectly consistent in his relations with Monica Lewinsky: that was the problem. He behaved exactly as a man with his record of casual encounters would be expected to behave when chased by an attractive and willing young woman who was pretty damn determined to have sex with him.

He has always been the prime example of a modern politician writ large. He does everything we expect politicians to do, just more so and more brazenly: twisting words, trimming tenses, massaging dates and facts, giving calculated emotional displays to distract from rational critique of his behaviour.

Like Ronald Reagan, he interpreted the bond of trust with the America people as a highly charged relationship and imbued it with the intensity of a love affair.

Mr Clinton is even better at this than Mr Reagan, whose movie-actor background invested too many of his performances with a recognisably manufactured edge.

The repentant sinner-president is a brilliant, cunning redefinition of the meaning of trust. The America people are asked to find a new kind of faith, in a fallible man to improve and to become whole again.

Set the opinion poll question, "Would you choose a man to lead you who is broken in spirit?" and the "Nos" would definitely have it. Yet by seeking to redefine his relationship with the American people as a communal odyssey towards Christian perfection, displaying his broken spirit in the way that Roman politicians seeking office had to display the physical wounds they had endured, he might just manage to save his presidency. The belief in redemption and change is the most powerful message of all: the reason Christianity has survived thus far and always will.

To adapt this to political ends might by cynical, but it is the only slight chance he has to recover the faith of America, and rewrite the trust-contract anew.

Back in our own, far less sensational soap-opera of power, where the best we can do for vicarious titillation is read about Robin Cook feeding Gaynor Regan's parking meter, questions of political trust are posed less dramatically. That does not make them less important.

Of all the indicators in The Guardian last week that were trumpeted as the bursting of New Labour's lovely big popularity bubble, the only one that will bother Tony Blair much is the 20-per-cent drop in the question about whether he is "more honest than most politicians".

Other ratings come and go; and as long as the Tory wheels go round and round in the mud, it hardly matters much to Mr Blair whether he is considered to be super-fabulously marvellous or just marvellous. But trust matters to New Labour more than to any other party because it has shifted so many of its other anchors.

When Mr Blair invited the country to trust him on the Ecclestone affair with the assurance that he is "a pretty straight sort of guy", he was moving the burden of proof away from the need to give a full account of what Bernie had or had not been offered in return for his donation, and on to himself as both the conduit and the focus of faith. Mr Clinton would have recognised the moment.

A sense of intimacy has been created around Mr Blair's relations with the public, implying a direct bond between electorate and leader that bypasses the institutions of power. Hence the gap between the rather aggressive and haughty Mr Blair seen at Prime Minister's Questions and the concentrated emotional intensity and swell of feeling evinced in the wake of Diana's death or after Omagh.

It is fashionable to find Mr Blair to be phoney, flaky and generally reprehensible for this. But I do not believe that this is the problem.

The gap which is widening and stretching the credibility of voters is between New Labour as the "people's party" and New Labour as the "party of business interests".

This is one of the reasons that I have a dull, uncomfortable, nagging fear about its unalloyed enthusiasm for businessmen and sponsorship and the sense that it will do - or not do - almost anything to preserve the love of entrepreneurs.

Party conference passes have just arrived ready for next month with the name of a supermarket printed along the lace that will be cast around the necks of those who attend. All of us will wander round Blackpool endorsing a grocery store. The whole identity of the party in government is to be visibly and ubiquitously subjected to money and its interests.

Criticism of New Labour's closeness to business is considered the preserve of those people who believe that the role of Labour is to oppose these interests and make life difficult for them. That was always a foolish position. Mr Blair was right in his assumption Labour could only become the natural party of government if it shed this knee-jerk hostility.

But he should beware of shedding too much caution with it. The great scandal of the corporatist democracies - Craxi's links with Berlusconi in Italy, the Flick funding scandal in Germany, President Chirac's embroilment in a favours scandal - all have their roots in relationships between politicians and business that have moved beyond the level of mutual helpfulness and into a sphere where hidden connections and obscure links determine what politicians stand for and how they run their countries.

That point has not yet been reached in Britain. If Mr Blair is wise, it will not be while he is prime minister. But the unease is there, the chink is open. Trust is a vulnerable thing.