The unremitting negativity and extremity of judgment of most of Murdoch's critics are amazing. Watson and Hickman never ask themselves why people like them were able for so long to tolerate a man now derided as the devil incarnate. Mr Watson is partly driven by personal motives — he was turned over by the Sun after he had led a conspiracy to force its hero Tony Blair to hand over to Gordon Brown — which he never examines. Nor does he reflect on the wider political revenge in which he is engaged.

Murdoch was tolerable as long as he was on Labour's side. Tom Watson's patron Gordon Brown became for a time at least as close to the tycoon as Tony Blair had been, united in part by their shared Scottish Presbyterian roots. When the Sun dumped Labour in September 2009, Brown allegedly rang Murdoch and roared at him for 20 minutes, ending up by telling him that he would destroy his company. During a hearing of the Commons Culture, Media and Sport Committee last November, an overwrought Mr Watson called James Murdoch to his face a "Mafia boss". That description might more accurately fit Mr Watson's former boss, Mr Brown, the capo di tutti capi.

In this sense Rupert Murdoch's decision to ditch Labour may have been one of the worst he ever made. He didn't particularly like David Cameron, and seems to have been leant on by James Murdoch and Rebekah Brooks, the Tory leader's friend and fellow member of the Chipping Norton set. In the months before the May 2010 election the Sun pulled out all the stops for Cameron but failed to win it for him, thereby suggesting, as Rupert Murdoch himself intimated during his recent appearance at the Leveson inquiry, that newspapers are not as powerful as politicians think they are. 

If the Sun had continued to support Labour, I expect the election result would have been much the same, and Murdoch would have been on the losing side, which he hates. But he would not have found himself as the Labour Party's, and the Left's, number one hate figure. The Guardian would doubtless have published its revelations all the same — after  all, the first knockout blow came in July 2009, a couple of months before Murdoch ditched Brown — though probably with less glee. He would have had a rough ride but not as rough as the one he has had. As for David Cameron, he would not be saddled with the accusation that he bartered his soul, and that of his party, for Murdoch's (ineffectual) support.

The only point of this slightly elaborate "What if?" is to illustrate how recent, unexpected and contingent the anti-Murdoch jihad is. It is mired in political calculation — or perhaps in political revenge. Beware those like Tom Watson and his fellow Labour members of the Culture Committee who, clothed in the raiment of virtue, recently made the preposterous declaration that Rupert Murdoch is not a "fit person" to run an international company.