Instead, they tend to go on to the point at which the tedium and repetition of their later years begins to obscure the reputation they established at the beginning. Only Fawlty Towers and Harold Wilson stand as examples of willing early departures from the scene (and some believe that Basil Fawlty was destabilised by MI5).
The far more common templates are those of Dallas and Margaret Thatcher: welcomes overstayed amid sad late days of ridiculous self-parody. Many, of course, never get the chance to go on too long. Again like politicians, television programmes are also subject to axeing and reshuffling at the whim of a handful of others. These removals and preferments send signals to different pressure groups within the profession.
Three current examples of this phenomenon underline the closeness of the parallels and allow conclusions to be drawn about the condition and difficulties of British television.
For example, Eldorado - the BBC 1 soap opera that leaves the screens on Friday after only one year - is clearly the Norman Lamont of television. Financially catastrophic - Eldorado cost the taxpayer pounds 10m, Lamont several billion - both were national laughing stocks and butts for newspaper humorists, yet nevertheless attracted some ardent admirers. (The Eldorado Preservation Society, a small group of soon-to-be-bereaved television viewers, is equivalent in this analogy to Lord Wyatt of Weeford, Lamont's staunch supporter. It is hard to decide which was the braver and lonelier position.)
There is, however, another parallel between Lamont and Eldorado, which Alan Yentob, the controller of BBC 1, would do well to bear in mind. The throwing overboard of such an item provides temporary relief and distraction, but the need for such a manoeuvre was the result of serious difficulties - in the Government, in the BBC - which have not gone away. Without Lamont, Britain still has a vast budget deficit and a demoralised administration. Without Eldorado, BBC 1 is still short of ratings, lacking money and part of a demoralised corporation.
The practicalities of replacement also loom. Mr Major had the voter-friendly Kenneth Clarke ready to plug the gap. Mr Yentob has set himself a very public test of his managerial capabilities through whatever he does to close the hole left by the failed soap. Sacking the media baddie, Yentob may discover, can only ever be a short-term solution.
If Eldorado were able to make a 'resignation statement' on Friday, it would, I think, make the Lamontian points that it had been driven out by the media and the real culpability was deeper in the culture of the organisation of which it had been a part. (Although Eldorado at least has the consolation that its superiors - Jonathan Powell, the ex-BBC 1 controller, and Peter Cregeen, the ex-head of series, were brought down with it.)
That's Life] - Esther Rantzen's series on BBC 1 that is to be cancelled after 21 years - is the Margaret Thatcher of television. Considered appalling by liberals and the educated middle-classes, it proved irritatingly popular among the C2s, who regarded its central visionary as a woman of almost saintly stature. But, hoping to go on and on, she eventually received a visitation from the 'men in suits' (Armani and Paul Smith suits on this occasion, as the programme's killers were John Birt and Alan Yentob), who persuaded her to go, pointing to a decline in popularity. The audience for That's Life] is roughly half what it was at its peak.
But the fall in audiences for That's Life] also illustrates the changes in British society and television since the programme's debut in the early Seventies.
That's Life] has its origins in a more innocent age. The fact that a mutant supermarket tomato might, in a certain light and held at a particular angle, mildly resemble a penis, or that the owner of a stationery shop was called Mr Blotter - the kind of humorous stuff on which That's Life] thrived - was regarded as slightly dangerous humour, perhaps even a kind of satire. The consumer campaigns that were the series' second element, essentially concerned mild corporate skulduggery or impoliteness.
The disparate ingredients of the series sat unconventionally, but not bizarrely, together. But the world has got harder and nastier. Perhaps because of this, television entertainment programmes of the Nineties - sociologists may wish to note - have tended to involve some element of con, humiliation, revenge and risk. These qualities all feature, to some degree, in the programming inventions of Noel Edmonds, Chris Tarrant and Chris Evans: television's new presentational holy trinity.
Alternate sincerity and whimsy - as practised by Esther Rantzen - now mainly gladden grannies. Her attempts to admit the darkness of modern life to the programme - through campaigns against child abuse and bullying - merely underlined the fatuity of the jolly material with which it was interleaved. It has always seemed clear to me, although Ms Rantzen disagrees, that the same format cannot easily contain jokes about phallic carrots and items about child abuse.
It would be wrong to push the parallels too far. Margaret Thatcher's ruinous adherence to the poll tax and Esther Rantzen's obsessive quest for a dog able to say 'sausages' are not exactly analogous. However, both examples are case studies of grand dames, warmed by the echoes of old applause, failing to detect a shift in the cultural climate. Nor do I think we can entirely rule out Dame Esther making pointed observations in the future about the difficulty the younger generation seems to be having replacing her.
The third example - ITN's News At Ten - does not resemble a politician. The proper comparison here is with HM The Queen. Both are national institutions of far more symbolic than actual significance. The politicians fighting to save the programme's current 10pm slot might like to explain exactly what is so indispensable about its present timing, apart from tradition. After all, a 6.30 or 7pm position (among those being suggested) would offer a potentially larger audience, being closer to peak-time. We are told that American news would be lost, but perhaps these politicians can provide us with a list of all the late-breaking US stories that have been on News At Ten in the past few months.
And, if John Major is so 'unhappy' with attempts to move News At Ten, why did he preside over a system which - by vastly raising the price of a third channel licence - encouraged ITV companies to maximise profits? Ingrained national habits - symbolic constancies - can be changed, as Mr Major acknowledged when he persuaded the Queen to pay tax. Expecting News At Ten to pay its way is no less an initiative of his own.Reuse content