Mr Clarke is in many ways the Cabinet's biggest personality, an upmarket lager lout to his critics, an intelligent and profoundly effective minister to his admirers. Disarmingly honest in public and private, he has made no secret of his ambition: 'I would like to be a contender for the leadership, but at a time of John Major's choosing.'
Mr Clarke is a bruiser - but one who delivers his blows with such geniality and gusto that many of his opponents remember him fondly, although usually only after he has moved on to his next job.
Having come from the party's pro-European left without ever having been one of the wets, he these days firmly rejects left/right labels, dubbing himself as from the 'hard centre' - one who believes in free market economics but enlightened social policy.
As Secretary of State for Health, he disarmed critics who feared the Government was set on privatising the NHS by declaring of private health insurance: 'I don't have it, you don't need it, we have a National Health Service'.
One of his first statements as Chancellor was: 'Anybody who thinks I came into office in order to dismantle the welfare state has not the slightest idea of where I come from nor my record.'
And when Michael Portillo, his Chief Secretary, and Peter Lilley, the Secretary of State for Social Security, were suggesting last year that the days of the basic state pension might be numbered, it was Mr Clarke who pronounced it 'an inevitable key part of the welfare state'.
Yet it was Mr Clarke who drove through the NHS market complete with its trusts and GP fundholders, and who - while Secretary of State for Education - gave the Government's reforms market- oriented twist by vigorously encouraging opt-outs to grant-maintained status. At the Home Office, he launched the Sheehy inquiry which proposed radical reform of the police, and a new generation of secure units for juvenile offenders.
His problem has been the Budget. At the time, it won plaudits from all sides of the party for balancing tight control on spending with tax hikes to cut the deficit while providing enough loot to defuse the VAT on fuel row. But the charge that it will leave the average family paying more tax than under Labour in 1979 has hurt.
To a degree, the Chancellorship has cramped his style. With the City watching every word, even as open and engaging a politician as Mr Clarke has to watch what he says. And he may yet regret his promise to resign if he is found at fault by the Scott inquiry.
Although, Mr Clarke probably needs an economic upturn before he again becomes man of the moment, he knows about up and downs. During the ambulance dispute, backbenchers were close to demanding his head, and he has watched Mr Heseltine, now favourite for the succession, regain that position after being declared politically dead over the pit closures issue.
Ever the realist, he has repeatedly remarked that those tipped to be Prime Minister are the ones who end up as the Prime Minister who never was.