"There is no human right to fried chicken." Nick Clegg provided the quotation of the week in his article for The Guardian. It was a defence of the Human Rights Act and a riposte to the Prime Minister's attack on human rights law in his article in the Sunday Express. Thus it illustrated two things. One is how strange coalition government is – something we notice only in the spaces in between the great political dramas. The other is how much better at it David Cameron is, because he understands the politics of impossible promises and the Deputy Prime Minister does not.
There is, indeed, no human right to fried chicken. Clegg was referring to a news story about a suspected car thief who climbed on to a roof and was eventually talked down. The police used a crane to deliver a KFC takeaway and the Daily Mail quoted a spokesman as saying that they had to "look after his well-being and human rights". But Clegg's rebuttal of PC Gawn Mad was curious. That news story appeared five years ago, and Clegg's vivid phrase about how the Human Rights Act is "manipulated" by "overcautious officials" had nothing to do with the current controversy over human rights law.
The problem at the moment, within the coalition, is over the Conservatives' plan to reform the European Court of Human Rights when the UK takes the chair of the Council of Europe, which supervises the court, in November. In his Sunday Express article, Cameron wrote: "We are going to fight in Europe for changes to the way the European Court [of Human Rights] works." Clegg glossed this in his article as wanting to "improve the timeliness and consistency of its decision-making", whereas Cameron and the Conservatives want to curb the court's tendency to expand on the rights laid down in the original convention in 1950.
Clegg's is the more realistic view, whatever you think of the purity of his liberalism or the quality of Cameron's populism. The chances of reining in the institutional bias of the court, in favour of saying that human rights are what the current judges say they are, are small. But Cameron's impossible promises are more democratic, in that they are in tune with the views of most of the British electorate.
It is the same with immigration. Anyone who has looked at the numbers for more than a minute or two can see that Cameron's promise to cut net immigration to "tens of thousands" is most unlikely to be fulfilled by 2015. Last week's figures showed that net immigration rose last year to 239,000, because the number of people emigrating fell.
But it doesn't seem to matter, because the Prime Minister's impossible promise gives an impression of what he wants to do. As on human rights law, he wants to do what the voters want, even if he cannot. The Liberal Democrats, on the other hand, seem to be opposed to what the voters want, even if their reasons are terribly sensible and practical. To take one random recent example, Tessa Munt, the Lib Dem MP for Wells, said plans to withdraw benefits from looters were "bonkers, bonkers, bonkers". Again, a vivid phrase and probably right but deeply unpopular.
Even on those subjects where Lib Dem instincts happen to chime with popular sentiment, they gain nothing. Opinion polls show that the public is sceptical about British military intervention in Libya, but the anti-war party has been co-opted into government, and Clegg has become chief explainer for why Libya is so different from Iraq.
It does not matter that the Prime Minister's foreign policy makes little sense. At the beginning of the Arab spring, in February, just as Egyptians were rising up after the example of the Tunisians, Cameron said in Cairo: "I am not a naive neocon who thinks you can drop democracy out of an aeroplane at 40,000ft." It turns out that what he meant was: "I am a sophisticated neocon who thinks you can drop democracy out of an aeroplane at 40,000ft" – which was broadly the policy in Libya.
At least Clegg believes in the liberal part of liberal interventionism. But his consistency or otherwise is neither here nor there. The only thing that matters is that the Prime Minister made a judgement in March when Colonel Gaddafi threatened to show "no mercy, no pity" in storming Benghazi: "We will come. House by house, room by room."
Helped by the London-centred view of the British journalist, the UK appears to be more of a player in Libya than it really is. This is a French-led operation, with French planes flying a third of combat sorties, and the Americans flying 27 per cent, according to Nato figures. Denmark has flown 11 per cent of bombing flights, with the British, Canadians, Italians and Norwegians flying 10 per cent each (although Norway stopped on 1 August). But in the British media it is Cameron's war, and he has won it.
It may not do him much good with the voters. They were notably ungrateful when Tony Blair saved the Kosovars and Sierra Leonians, but it probably does a prime minister some good to be seen as a leader of consequence on the world stage.
Thus Cameron makes coalition government work for him. Clegg sometimes thinks it works for him, in those moments when he believes all that Lib Dem happy talk about pluralism and coalition politics and how they do things better in Belgium. Er, Germany. Or possibly other places in continental Europe. But a brutal assessment is that the Lib Dems are invisible in foreign affairs and when they attract attention at home it is for things, like the human right to fried chicken, that put voters off.
For all its novelty, coalition is a phase in British politics that may have surprisingly little lasting effect. No wonder people have been pointing out, again, how neat it would be for Cameron to appoint Clegg as Britain's next EU commissioner when a place falls vacant in 2015.