When his friends are jailed for dishonesty or named as conspirators in a bank fraud trial in Arkansas, he throatily defends their honour. How loyal! When Hillary Clinton is depicted swapping martyrdom anecdotes with Mahatma Gandhi during "virtual therapy" sessions in the White House, the President takes her to Nashville for a conference on family values and embraces her before the cameras. How chivalrous!

Scandal follows embarrassment in a permanent cycle, yet Mr Clinton seems to float above the fray like a naughty but lovable schoolboy caught with his fingers in the biscuit tin. Pity poor Robert Dole as he tries to devise a strategy to beat an incumbent who has finally mastered Ronald Reagan's folksy yet dignified style of presidency. And Mr Clinton also appears to have stolen the Gipper's Teflon coat, along with several of his policies. Polls show him with a lead of up to 20 points which is showing no signs of erosion.

If the Republicans are sensible, they will not try to make Whitewater an issue in the November election for one simple reason: Americans know there is something highly dubious about the Clintons' financial dealings in Arkansas and much of their behaviour since reaching Washington. Yet they do not care. The opinion poll data are unambiguous. One recent survey found that fully two-thirds of American voters believe that Mr Clinton has done something either illegal or unethical in his Whitewater dealings. But four-fifths of voters say it will not influence the way they vote in the autumn. Notwithstanding his recent battering, 57 per cent of voters say Mr Clinton deserves a second term, against the 52 per cent who said the same of Ronald Reagan in 1984.

There is no compelling reason to want to eject Mr Clinton from the White House, unless there is a more attractive alternative. At the moment, there is not

How can this be? First, American voters have exceedingly low expectations of their political leaders' ethical behaviour. It is remarkable what can be got away with in US politics. The importance of the character issue, even in presidential politics, can be exaggerated. Mr Clinton won the 1992 election after voters had a pretty clear idea of his flaws. They are unlikely to reject him for those same reasons four years later.

There is some geographical snobbery, too: most Americans assume that people from Arkansas sleep with their sisters, so are hardly scandalised to discover that the state's political and business elite has its fingers in the till.

Another factor is the strong performance of the American economy, with low inflation and unemployment, and a shrinking budget deficit. The tax increases of the first Clinton budget did not, as the Republicans predicted, pitch the economy into recession.

For most voters there is no compelling reason to want to eject Mr Clinton from the White House, unless there is a more attractive alternative. At the moment, there is not. The Republicans have won all the important arguments, even Mr Clinton now says the era of big government is over. But they have not been able to sustain the momentum of their 1994 congressional landslide. They are divided on issues ranging from abortion to a flat income tax. To many Americans, Mr Dole simply does not look like a man likely to become president.

The strategy may have been brazen but it has worked for Mr Clinton is no longer threatening to Middle America

But the main explanation for Mr Clinton's current good political health is his ingenious and shameless reinvention of himself. Bob Woodward's new book recounts the sense of crisis and betrayal in the White House after the Democrats' calamitous defeat in the 1994 congressional elections. Mr Clinton blamed his advisers for the disaster and spoke about "traitors on my staff". But when it dawned on him that he was being punished by voters for being too Left-wing, he approached Dick Morris, a Republican image maker, to re-cast his presidency.

The old guard of liberals who masterminded his 1992 victory were shunted aside. Mr Clinton systematically pre-empted the Republicans on issues like crime, welfare reform, the war on drugs, crime victims' rights, and homosexual marriage. On all these issues he took, without blushing, a Right-wing position that makes his old friends gasp in disbelief.

The strategy may have been brazen but it has worked for Mr Clinton is no longer threatening to Middle America. You hear it driving around the heartland on the call-in radio shows, which were previously hostile to him. Today, he is as likely to be praised as attacked by the callers and the hosts.

All this is not to say that the future is rosy for Mr Clinton, for Whitewater and its related scandals will not simply go away. But they will have limited impact on public opinion until the edifice of the administration actually starts to crumble, and this is unlikely to happen before the November election.

15 May 1996: Dole campaign to woo women

25 June 1996: Clinton escapes pre-poll sex trial