There is a remark – no doubt apocryphal – attributed to the new BBC Director-General, George Entwistle, when he was the editor of BBC2’s Newsnight: an exhortation to his team to see how they could f*** the government that day.

In the UK, news and current affairs programmes are bound by obligations to impartiality, entrenched in the BBC’s Charter and Licence, and – for commercial stations – in the Ofcom rule book. Recently, a news channel reflecting views from Russia was rebuked by Ofcom for lack of impartiality, after complaints about its reporting from Libya and the frontiers of NATO.

Yet current affairs programmes are by their nature inquisitive, investigative and interrogative: and the normal object of their inquiries will be those making and implementing policy. They may adhere to impartiality requirements in the way they report, but their agendas are inevitably shaped by the world they observe.

In the US, the rise of radio shock jocks and strident cable news services has marginalised the staid reporting of the network news programmes. Liberal commentators bemoan the corrosive influence of Fox News, which out-rates by a wide margin the countervailing offerings from MSNBC and CNN.

Less noticed had been a drama series on HBO, which has just finished its run in the UK on Sky Atlantic: 'The Newsroom' – the latest offering from the inventor of 'The West Wing', Aaron Sorkin. 'The West Wing' told the story of a Democratic President, in a clearly sympathetic way. 'The Newsroom' has gone much further.

'The Newsroom' has two conceits. The first is that each episode is set in the recent past, re-inventing how a one-hour peak-time cable news show – coincidentally entitled "Newsnight” – might have reported the news. The second is that its host and new executive producer (inevitably, a romantic item in the past) have embarked on a mission to educate the American public.

This quixotic enterprise follows a moment of revelation in a college debate when the host is asked by a student to sum up – “in a sentence or less” – why America was great. He attracts instant notoriety by asserting that America was not great (listing its many failings by world standards) but might one day become great again.

The host – Will McAvoy, played by Jeff Daniels – identifies the main reason for American backsliding as the rise of the Tea Party. Sorkin tries to finesse the party political dimension of this approach by designating McAvoy as a Republican shocked by his party’s lurch to the right under pressure from these insurgents. McAvoy, on air, acknowledges that he is now labelled a RINO (Republican in name only) but is determined to reclaim his party by dint of reasoned analysis and argument.

The two conceits are massive drawbacks in terms of the dramatic impact of the series. The Sorkin trademarks of snappy dialogue and tortuous love triangles are played out – wholly unconvincingly for anyone who has worked in a newsroom – in full view of the production team, which every so often breaks out into non-ironic applause. There is so much 'wisdom after the event' that even Christopher Tietjens’ prediction, almost to the day, of when the Great War will start (in the BBC’s impressive 'Parade’s End') seems only mildly prescient by comparison.

For the most part, 'The Newsroom' allows the production team of Newsnight to shoot fish in a barrel, with clips from the offending politicians heavy-handedly pulverized by the righteous McAvoy. On one occasion, a “real” supporter of a Tea Party politician is asked repeatedly if he is offended – as a gay man – by that politician’s evident belief that homosexuals are inferior humans. Just this once, McAvoy is put in his place by the invented character, for attempting to define him exclusively in terms of his sexuality.

And that’s it for the bad guys. Indeed, when Newsnight succumbs to pressure from ratings losses to cover the trial of alleged child murderer Casey Anthony, it is solely in order to be allowed to stay on the air long enough to mount a full scale “debate”, in which all the leading Republicans adhering to Tea Party ideology – played by members of the production team – are to be duly interrogated by McAvoy, to predictable effect.

Does 'The Newsroom' bear any relation to reality? On CNN, Anderson Cooper often debunks know-nothings like Michele Bachman in his AC360 show. I was helpless with laughter after one of his interviews with a Republican “birther” congressman who doggedly continued to doubt Obama’s Hawaiian birth certificate even after Cooper displayed a copy on screen; but Cooper mixes this up with other news stories, and more light-hearted fare (check out his “ridiculist” online). And Jon Stewart and Stephen Colbert also regularly lampoon the obvious Republican targets.

However, In the UK, we concentrate on the right-wing bias on US cable news, most notably on Fox News, where many leading Republicans find regular employment. During the NewsCorp bid for BSkyB, the possible conversion of Sky News to something more like Fox News was often invoked by opponents of the deal.

As it happens, although the news agenda can be massaged – compare Channel 4 News with ITV News, both, as it happens, supplied by the same company – it would be impossible to turn Sky News into a right-wing rant, even if anyone wanted to (and there is no evidence that anyone does). In fact, Sky News is a well-watched and well-regarded news service, whereas Fox News – which is indeed already broadcast in the UK – is completely ignored.

So to see a high-budget, high-profile drama series take direct and steady aim at right-wing ideologues is at one level exhilarating, not least because the HBO series was carried in the UK on BSkyB’s Sky Atlantic, despite a storyline in 'The Newsroom' coming within a whisker of directly accusing James Murdoch of organising large-scale hacking of phones and computers at the News of the World.

Of course, that the dramatic impact of the series was undermined by its implausible and shrill characters, and by the insufferable smugness of its political correctness, somewhat mutes one’s enthusiasm for the abandonment of any pretence at impartiality – even Fox News tries to describe itself as “fair and balanced”.

Yet that HBO commissioned and broadcast such a full-throttle critique of the new right-wing orthodoxy took me back to the 1960s, 1970s and 1980s, when 'The Wednesday Play' and 'Play for Today' on the BBC gave airtime to writers, directors and producers like Jim Allen, Roy Minton, Alan Clarke, Alan Bleasdale, Dennis Potter, David Hare, Ken Loach, Tony Garnett, David Edgar, Trevor Griffiths, Stephen Poliakoff, David Mercer, David Storey, James McTaggart, Margaret Matheson and Richard Eyre.

Those heady days at the BBC are long over. Gordon Newman’s brilliant and subversive 'Law and Order' (unconnected to the US series) was broadcast 35 years ago; Troy Kennedy Martin’s 'Edge of Darkness' 27 years ago. Nothing like them has been seen since, though Newman is reported to be working still on a sequel.

The nearest we get to “political” drama today is the tepid 'The Hour', set in the 1950s, whose second series is about to be transmitted. Hare and Poliakoff are still allowed the occasional outing, with predictable jabs at the class system, but truly radical drama is nowhere to be found. The great swaddling effect of impartiality – in which so many take pride – insulates drama from passion.

'The Newsroom' has many flaws as drama: but it certainly does not lack passion, or political acumen. Most impressive of all, HBO had the courage to broadcast the series in an election year, just when the lies and demagoguery of the Tea Party most needed exposure. Series two will be transmitted next summer. Any possibility of some red-blooded political drama before then from the BBC, George?