For some time I thought that the Twenty-Second Amendment to the United States Constitution was probably the best way to ensure that political leaders do not overstay their welcome, and, just as importantly, wear out their effectiveness. This Amendment bars US Presidents from holding office for more than two four-year terms.

Perhaps I had forgotten the travails of President George W. Bush’s predecessors in their second term, but his own current predicament shows that the constitutional limit has its own problems. For one thing, it makes the President a lame duck sometime in his second term. Does anyone remember that after his re-election Bush promised to reform the pension system (“Social Security”)? Now he is clearly hamstrung not only by the Democratic opposition, but also, and perhaps more so, by the succession struggles within his own party.

However, the fate of Bush’s friend, British Prime Minister Tony Blair, shows that lame-duck status can occur even without a constitutional term limit – indeed, without a written constitution at all. Blair made the fatal mistake of setting his own limit to his tenure of office by saying that he would not contest a fourth election as leader of the Labour Party. But, even without such a vow, he would find it difficult after nine years in office to combine a program of reform with a sense of what can be achieved given the mood of his party and of the country.

Indeed, reforms announced by Blair increasingly sound like empty promises, because the apparently inevitable has happened: the Prime Minister has lost touch with the public. What used to be his charisma is now the permanent re-enactment of the all-too-familiar.

Of course, it is always very hard for leaders to relinquish power. Some have done so, more or less voluntarily, only to re-emerge suddenly from oblivion. Can it be the same President Oscar Arias who (barely) won the recent presidential election in Costa Rica and now returns to power after 20 years? And was not Silvio Berlusconi’s candidate for the presidency of the Italian Senate, Giulio Andreotti, a junior member of one of Italy’s first post-1945 governments? Did Portugal’s Cavaco Silva, the successful Prime Minister of the 1990’s, have to reappear as President in 2006?

Who can forget Margaret Thatcher’s tears when her “friends” told her that her time was up? When Prime Minister Harold Wilson suddenly resigned in 1976 and left No. 10 Downing Street to the late James Callaghan, people became suspicious: had he been forced out by some secret service plot concerning South Africa?

It appears that there is no way for political leaders to leave the scene gracefully. Even if there is an “orderly transition” – a term much used about Tony Blair and Gordon Brown at the moment – it is accompanied by sorrow, or at least by pain. Political office, it seems, is more addictive than heroin. Abandoning the habit involves not only the inconvenience of losing perks and a certain lifestyle, but also the loss of power. Power may be increasingly illusory in a globalized world, but it is an illusion that is shared by others, and the longer one inhabits it, the more one’s circle consists of others who share the belief.

The addiction to political office is always worrisome, because democracies turn into autocracies when leaders cease to recognize the limits of their power. Disconnection is the beginning, followed by the belief that one is the only person who knows what is right and good. When Tony Blair says that the most important liberty is security from terrorist attacks, he has forgotten the first principles of his party and his country. Overstaying one’s welcome may be the professional disease of political leaders, but it is above all incompatible with democracy as a framework for bringing about change without violence.

The question, then, is whether there is any way to ensure that political leaders leave in time. While the US Constitution shows the limits of institutional safeguards, the role of political parties is clearly significant when it comes to limiting terms in power. Like Thatcher, Blair now hears from his party that he should go and replies that “the people” still want him. Yet the party might have a better sense of what is viable not just today, but also tomorrow – at the next election, for example.

In the end, there is no foolproof method to guarantee that political leaders leave without tears. What matters is that mechanisms are in place that do make them leave, probably rather too late, and certainly with some pain and unhappiness, but in time for the constitution of liberty to remain intact.