If a right-winger fails to play to stereotype by saying he believes the evidence for global warming is overwhelming or the left-winger says she has her doubts about the euro, they unbalance the debate and — more importantly — confuse the viewers and listeners. Pundits' personalities need to be simple and predictable to hold their attention. Complexity or deviation from the roles assigned by central casting upsets the audience as much as the broadcasters.

The result is a media that cannot handle large sections of political opinion. Many Labour supporters are against immigration and the European Union but for the welfare state and the redistribution of wealth. They are unrepresented in both print and television. Only The Times provides a space for Cameron-style compassionate Conservatives, who believe in fiscal conservatism and increasing the foreign aid budget. 

As for politics itself, British commentary has no way of dealing with the cross-party alliances that, for instance, support early and expensive intervention in the lives of deprived children but also support cutting the overall costs of welfare. Unlike politicians, when commentators talk about welfare they must either say that benefits can only rise (if they're left-wing) or that they are incitements to idleness and immorality that must be slashed (if they're right-wing). What percentages of the population share the caricatures of left- and right-wing politics the media present is hard to say. My guess is that they have always been far smaller than editors imagined and are smaller still now. 

The recession has destroyed old certainties. Gordon Brown's idea that you could let the financial markets rip and then use the proceeds to fund Fabian projects crashed with the banks. But so too did the belief of economic liberals that markets worked best when left alone. The pressure of events is changing minds and sending previously fixed ideas into flux. Everywhere, that is, except in the media.