One reads the headline in the morning’s Telegraph with that familiar crushing feeling: ‘Oxford Tories’ nights of port and Nazi songs’. A gruesome illustrated litany follows, listing the less wholesome doings of members of the Oxford University Conservative Association. The Telegraph, whose known editorial politics make the article unlikely to be motivated by party political considerations, indicts OUCA on the counts of "anti-Semitism, debauchery and snobbery".

The Telegraph’s online edition confirms that it is not déjà vu one is feeling. We are invited to click on ‘Related Links’ to articles headlined ‘Oxford student Tories in racism row’ (June 2009), and, with comic predictability, ‘Oxford student Tories in sexism row’ (June 2010).

"These are the frailties of youth, and most grow out of them. Finding oneself the subject of a withering report in the Telegraph is unlikely to hinder the process."

Perhaps one is being too charitable, but it is difficult to believe that OUCA is an unequivocally or even predominantly racist (sexist, elitist, anti-Semitic...) institution. That its officers have been sufficiently moved to protest, and to resign, tells against the need for an outright condemnation.

Those who count the association’s members and ex-members as friends might have even stronger reason to seek an alternative interpretation. The simple fact of personal acquaintance with those involved in these rows makes one suspect that they say racist (etc.) things not because they are racists, but because they are – to use the technical terminology – idiots.

Now idiocy is not exactly a moral vice, and it has its innocent forms. What the Telegraph quaintly terms "debauchery" is a foible to be found outside OUCA. There is perhaps something to be said about the class connotations of OUCA’s traditional choice of tipple, but there is the strong likelihood that a 19.5% alcohol content has at least as much to do with it.

However, the other shenanigans of OUCA’s members described in the article don’t quite make the cut. Granted their sins are but venial, that they are likely being stupid rather than evil. But this needn’t be the end of the story. A drunk undergraduate in fancy dress is not the moral equivalent of a Ku Klux Klansman, despite that hood he’s got on his head. But we do not therefore have to withhold our judgment on his culpable stupidity.

One part of the distinctive stupidity of these young Conservatives is ignorance, of the actual history of the Third Reich, say. Another is imprudence, or they might be more concerned about the effects of their actions on their future careers. Yet another is insensitivity, an absence of the imagination that might help them to reckon other people’s feelings, and an indifference to those feelings when they are known. These are, to use a cliché, the frailties of youth, and most people grow out of them. Finding oneself the subject of a withering report in the Telegraph is unlikely to hinder the process.

There is a yet more worrying aspect to OUCA’s idiocy, and it is one shared by many of the Telegraph’s grown-up readers. This is usually captured in the platitude about "political correctness run amok". On this view of things, Britain is in the control of an insidious regime that puts criticism of certain things – immigration, feminism, gay rights – beyond the pale. The so-called offensiveness that others criticise is rather to be actively commended for breaking these taboos.

However, the sheer ubiquity of these claims of being silenced should suffice to refute them. And one might be forgiven for wondering about the selective suddenness of a concern among the British right with unfettered expression.

There is, no doubt, a legitimate criticism to be made of what Archbishop of Canterbury Rowan Williams succinctly labelled a "wooden-headed bureaucratic silliness combined with a well-meaning and completely misplaced anxiety about giving offence". To use this as a defence, however, is to want to behave obnoxiously (as even the Telegraph agrees) and to give it the name of freedom.

The worst thing about the idiocy of student Conservatives is that it is so often defended as humour, a defence captured in that panacea of a phrase, "just having a laugh". As if humour were exempt from the requirements of common decency.

A yet more pernicious variant of this defence invokes the sophisticate’s ultimate trump: irony. On this view, not only are the port-sloshed young Tories under consideration defenders of humour itself, but the real radicals whose offensiveness is in fact a sophisticated parody of real racists, real sexists (which of course they’re not). Certainly, the parody of racists is, in the right contexts, a powerful political statement. However, these contexts do not typically arise after a third of a bottle of port.

No one thinks that tellers of ‘ironically’ racist jokes are, or are just as bad as, racists. Although it must be said that there are those who pretend to be racist to conceal the fact that they are, and that there is such a thing as the mask that eats into the face. Venial their offence might be, but a disproportionate penchant for humour of this variety does make one think: sure, it might indeed all be a laugh, but why laugh at these things in particular? Why is ironic offensiveness to be the default register of the chat over port?

The narrator of Julian Barnes’s recent Booker-winning novel, The Sense of an Ending, describes the temperament of a friend: "We were essentially taking the piss, except when we were serious. He was essentially serious, except when he was taking the piss." It is hard to say which of these attitudes is the preferable one. But they are both preferable to a convenient inability to tell the difference between being serious and taking the piss.

Those of us who keep company with decent people are perhaps familiar with that awkward silence when the taboo-busting ironist crosses some invisible line, and the inevitable, "Actually, that’s not funny." The ironic racist thus caught out is not a martyr to the humourless; he (and it is usually a he) is a failed humourist. Ever to claim the vindication of irony is to want to say anything and be judged for nothing. It is to want freedom without responsibility.

Responsibility, seriousness, prudence, and an acquaintance with the norms of propriety: is it fanciful to hope that this is what Conservatism could be about?