Earlier this year, when the phone-hacking scandal was monopolising the news, quite a few MPs seemed baffled - not by the anger itself (no one could doubt that appalling behaviour had been exposed at the News of the World), but by the apparent scale and momentum of events. Plainly it was a huge news story and journalists like few things more than writing collectively about themselves. But the question being asked inside the Westminster village was "how big could this get?" There were some stunning personnel changes. The Met top brass resigned; a mass-circulation Sunday newspaper closed its doors. But when the dust had settled, how different would the landscape really look?

MPs weren't hearing about hacking from their constituents. The two issues most often raised on the doorstep and in surgeries continued to be the economy and immigration. That made a marked contrast with expenses scandal, which ate the political agenda much as hacking did but which also turned into a huge issue for individual MPs on their home turf. People still talk about it. Pollsters say it is one of the few things that those voters who are generally uninterested in politics can recall about Westminster goings on. That is not the case with hacking. For parliament and the media and the Murdoch family, it is big news. For everyone else, it is part of a background blur of shabbiness and name-calling - the relentless and inchoate hum that tells people politicians and journalists are generally scummy, but not much else.

One senior shadow cabinet minister I spoke to at the time expressed it in interesting terms, I think, when he considered the possibility that it was a "Diana moment - where everything seems to change and in fact nothing changes." There was a short burst of hysteria - a particular national mood - and then it dispersed. The monarchy changed a bit; the paparazzi didn't change at all. Business continued mostly as usual.

James Murdoch's appearance before a parliamentary committee today was important, revealing and necessary. But it is not a national event. It doesn't stoke up wider feelings of anger and rage about hacking. There was a fire there once, but it has gone out.

This is something to which Labour and Ed Miliband should be paying careful attention. The phone-hacking scandal was his moment. He made a difficult and brave judgement call - took a risk - and got it right. It was a turning point in his leadership. But Miliband and his team read more into it than that. They tend to interpret the success over phone-hacking as a sign that there are untapped reserves of political capital available for the candidate who takes on powerful vested interests and wins. If Labour could reverse the orthodoxy that said you have suck up to the Murdoch empire, what other orthodoxies of recent political memory might be ripe for reversal? It was an episode that emboldened Miliband and encouraged him to develop more broadly the language of "vested interests" and"ripping up the rule book" and "predatory capitalism" as expressed in his party conference speech and in last week's article in the Observer praising the St Paul's protest.

I don't doubt that this is an intriguing line of thinking and that it might prove fertile political terrain for the leader of the opposition. Maybe it is, as Labour must hope, the kernel of a winning strategy. And I know, of course, that it is premised on more than just the buzz that came from banging in some political goals during the phone-hacking saga. But that was certainly part of it and it is instructive how unmoved most people (outside Labour circles and the Guardian) really are by the issue. Maybe they should care more. The accrual of power and its abuse in the Murdoch empire -not to mention allegations of criminal behaviour - are serious matters. But I'm not persuaded that many voters are ready to read across from that to anything like the conclusions that the Labour leadership has drawn.