Magnetic leaders arouse a special loyalty, a power which fascinated Freud, who contrasted them with authority figures who merely command respect for their expertise. Charismatic leaders, argued Freud, have the knack of penetrating their followers' psyche, triggering identification and dependency. So Tony Blair, like Bill Clinton, is (or was) an appealing leader because he focuses on the human needs of his followers. He seems to be a "real" person rather than a politician, Much has been made of the "Blair effect" in Labour's 1997 election landslide, but David Sanders, a political scientist in the department of government at Essex University, has attempted to quantify precisely the party leader's contribution to that startling success. Using computerised calculations, Sanders reckons that Blair personally cost the Tories around eight percentage points of the popular vote.
But charismatic leadership is not without its problems. Stewart McCann, of University College of Cape Breton in Nova Scotia, has recently found that the younger you are when you achieve greatness, the lower your life expectancy. There seems to be an intriguing link between precocious achievement and poor long-term health: Tony Blair was 43 when he became prime minister, the youngest since Lord Liverpool in 1812.
McCann looked at 22 samples of high achievers such as prime ministers, popes, Supreme Court judges, and Nobel prize and Oscar winners. In almost every case he found that the youngest achievers died earlier. He suggests this is because high achievers generally score highest on Type A personality tests. This chimes with medical research which shows that people with Type A personalities are vulnerable to cardiovascular disease.
Type As are competitive, excessively driven and aggressively aspirational.
They're easy to spot: they have tense muscles, an alert and rapid speech style, and are manically active. Because they are so "goal directed" (pushy), Type As are also irritable, hostile and easily angered. They find other, less ambitious, people get in the way, which leads to enormous frustration when they don't get what they want. They are absolutely convinced that they are right.
Such apparently delusional leaders can bend reality to fit their vision.
Winston Churchill probably seemed a bit delusional when he insisted Britain would fight off an expected German invasion in 1940. But in the end, his implacable conviction helped save the country. It is an example of a charismatic leader making something happen through the force of his personality.
Perhaps the lesson to learn from Blair's fall from favour is that, having secured trust and loyalty, it is vital not to take it for granted; leadership has responsibilities which must be discharged not abused.
Followers may pledge loyalty to their leaders, but if they feel betrayed, their anger can bring down even the most powerful ego.
Dr Raj Persaud is Gresham professor for public understanding of psychiatry, and director of the Centre for Public Engagement, King's College London.
His latest book is The Motivated Mind (Bantam Press). Email: firstname.lastname@example.org