The ghost of Margaret Thatcher has been resurrected this week, as a warning to the Labour Party not to eject Tony Blair against his will.
The Times was fairly typical: "The example of the Conservative Party, which is only just beginning to recover from the trauma of Margaret Thatcher's political assassination 16 years ago, should send shivers down the Labour Party's spine."
The Times, and all the other ghost-mongers, are wrong. Before myth displaces reality completely, it's worth recalling what happened to the Iron Lady. For the moral of her downfall is exactly the opposite. It is that a swift execution can help, not hurt, a party pondering changing its leader.
For those who have forgotten what happened in 1990, or were too young, or simply enjoy political nostalgia, here are the key events. On April 1 the poll tax arrived in England and Wales (it had already been introduced in Scotland). It was a terrible, ill-thought-out and profoundly unpopular measure. Polls taken in March, when agitation was at its height, showed the Tories miles behind Labour, and Thatcher's personal ratings plunging to new depths.
Oddly enough, some of that hostility receded once the poll tax actually came into operation. Many people discovered it would not hit their pockets quite as hard as they feared. Yet Thatcher remained damaged goods. When, in November, she launched an anti-European tirade, she provoked Sir Geoffrey Howe to resign as deputy Prime Minister, and Michael Heseltine to trigger a leadership contest.
The winner, of course, was John Major, the man who went on, in 1997, to lead the Conservative Party to its worst defeat in its history. Hence this week's scare-laden notion that to dump a three-times election winner is to court long-term disaster. Yet this analysis ignores what happened between 1990 and 1997. Sixteen months after he became Prime Minister, Major led his party into the 1992 election. True, the Tories lost seats. But they remained in office, and actually increased their vote. Indeed, the Conservative vote of just over 14 million set a new record, which no party has yet surpassed, not even Labour in 1997.
It was only afterwards that Tory support began to unravel. A number of factors combined to make the party unelectable: Black Wednesday, when the pound was forced out of Europe's exchange rate mechanism; the rows and divisions over Europe, especially the Maastricht Treaty, and exposes of sleazy behaviour by leading Tories. Of these, the only issue that can be said to have involved Thatcher's ghost was the rebellions over the Maastricht Treaty, by right-wing, Thatcherite backbench Tory MPs. But these divisions were already evident at the time of Thatcher's departure. Had she survived Heseltine's challenge, the issue would have persisted. The Tory party would still have faced fierce internal strife. The lesson for Labour is not that Blair's swift departure is necessarily fatal for the party. Rather it is that Gordon Brown (it is hard to see anyone else winning the party's leadership contest) must work to sustain his likely honeymoon with the voters. This will involve maintaining his reputation for economic competence, acting decisively to clean up politics and giving a sufficiently firm lead on policy issues to prevent Labour descending into civil war over Government strategy.
I see no reason why Mr Brown should not achieve all three things. Above all, there is nothing doctrinal these days that divides Labour MPs as fiercely as Europe divided the Tories in the 1990s.
To avoid any misunderstanding, I should stress that this analysis is not intended to say to Labour MPs: go ahead and force Tony Blair out tomorrow. There are various arguments for and against any specific timetable for his departure.
But the lesson of Thatcher's political execution should not be used to argue for delay. If anything, her exit provides evidence that Labour could benefit if its leadership saga turned out to be nasty, brutal and short.
* Peter Kellner is chairman of polling firm YouGov.