Ah, the paradoxes of politics. In order to be seen as authentic, Gordon Brown has to do what he regards as inauthentic, namely to emote on television. Long ago, the authentic Brown said, "I can't stand all this touchy-feely stuff." In an interview in Novem- ber 1997, he seemed to be free-associating when he was asked about the rebranding of Britain. "All this talk of whether we're about the Spice Girls or Vera Lynn is ridiculous." It was a curious sequence of non-sequiturs – and therefore all the more revealing.
When he became Prime Minister, there was a sigh of relief from all households in which the reticence of Clement Attlee is revered, because we did not have Tony Blair drama-queening around every time the word "crisis" was in the headlines. That phase lasted about five minutes.
Here we are, then, back in the 21st century, and Brown is on television tonight talking about the death of his child and how much he loves his wife. He has done it all before, but it was just not working then. Kay Burley made him cry on Sky News soon after he became Prime Minister (just as her colleague Adam Boulton exposed another emotional side of him more recently, pushing him close to losing his temper on camera). And he paid a glowing tribute to Sarah Brown in his party conference speech last year, a speech that she introduced by paying a glowing tribute to him.
Something has changed. We know that, in his heart, he still does not really approve of this touchy-feely stuff. Yet some internal switch has been flicked, and some inhibition lifted. A change came over him before Christmas: he was still exhausted but was suddenly more at ease with himself. He started to make jokes in the House of Commons; he negotiated brilliantly at Copenhagen, even if it came to nothing; and his enemies (those are the ones on his own side) were in disarray, as were his opponents. Tonight's performance, therefore, is now a triple bluff. It is an inauthentic attempt to appear genuine, but the very fact that Brown is happier about doing it lends a kind of authenticity to the exercise.
Brown recognises, reluctantly, that times have changed. Charlie Whelan, his "professor of rotational medicine", as Rhodri Morgan once described the role, a role that Whelan continues to fill in his nominal trade union job, said when his boss's honeymoon ended: "We live in much more of a celebrity-dominated culture now... so you can be hero to zero in no time at all. This is not the kind of politics we had when Ted Heath and Harold Wilson were around." You have only to think what journalists would make of Heath's private life now to see how true that is.
That may be a shame if it limits the pool of talent from which political leadership can be drawn, but it is a fact about which there is no point in complaining. Nor is it even obvious that Attlee-nostalgics should complain. We seem to be able to have an opinion – increasingly a favourable one these days – about Peter Mandelson as a politician, although his private life remains firmly private. Equally, if politicians want to tell us about their private lives we are interested. We are, after all, human.
We use all sorts of cues as proxies for political judgement. This is especially important for opposition leaders that have limited executive experience. That is why the family lives of Tony Blair, Barack Obama and David Cameron have featured so prominently. Blair is a good example of someone whose family life was the message. He embodied aspiration, and lived the middle-class life that New Labour promised the many not the few. One of the lesser reasons why he has become so unpopular, I suspect, is that he appears to live a different life now, one that is out of touch with Middle England.
One of the more persuasive reasons for voting for a party led by Cameron is that he is married to someone who was a member of Greenpeace and wanted to play "Wonderwall" as they walked up the aisle at their wedding. ("Look, I am a Conservative; I cannot allow this," Cameron protested.)
Likewise, Michelle Obama's speech to the Democratic Convention was a cut-through moment in the 2008 presidential election. As David Plouffe, the campaign manager, says, "It was our best opportunity – better even than Obama's own speech – to show what kind of person Barack was." In his memoir of the campaign, The Audacity to Win, he wrote: "There were shadowy suggestions floating both virally on the internet and in the mainstream press that he was un-American, a Muslim, an elitist, a privileged phony." Michelle rebutted them, most memorably with her line about Barack driving home with their new-born daughter, "inching along at a snail's pace, peering anxiously at us in the rearview mirror, feeling the weight of her future in his hands ... determined to give her what he never had: the affirming embrace of a father's love".
No doubt Sarah Brown will find a platform – apart from Twitter, that is – to do something similar here.
And it is not as if such confessional material will take up bandwidth at the expense of serious in-depth coverage of policy issues. In fact, in the coming general election, quite the contrary. This time, more than ever before, we will have it all. Because we shall have the television debates. A common complaint about personal interviews is that they represent the further Americanisation of our politics. But it is not as if we have never done such things in this country before; whereas the one thing that we have not done before is to copy the US tradition of a series of long televised debates, which is one respect in which their political culture is more serious than ours.
It is not to everyone's taste, but Brown was not wrong to be interviewed by Piers Morgan for tonight's programme, and we should give him credit for deciding that he can stand "all this touchy-feely stuff", after all.
John Rentoul blogs at www.independent.co.uk/eagleeye