When there were only a handful of broadcast channels, there was a case to be made for regulation, and requiring broadcasters to be politically impartial. It didn't work, of course, as there is no such thing as true impartiality, but most broadcasters in Britain genuinely tried and I suspect that in the early days, so did US broadcasters.
But today, I have four 24-hour news channels. Ninety six hours of news a day is enough even for a politics-geek like me. So how do I choose? Most people choose their newspapers by political persuasion and style of presentation. This is especially so in the UK, where there is a highly competitive national newspaper market.
In the future, that is the offer that broadcasters too are going to have to make. To establish a loyal customer base - one that doesn't channel hop indiscrimintately, they will have to appeal to specific market segments. That is what is happening in the US. CNN has more or less stopped pretending to be anything other than a liberal network. Equally, Fox is the network of choice for conservatives. CBS, ABC and NBC try to maintain the myth of neutrality, but this is increasingly strained. Most people know that all three - especially CBS - are liberal.
This will happen in the UK too. It is how markets work, and how ideas compete. As Charles Krauthammer put it, "Fox came about because Rupert Murdoch spotted a gap in the market: 50% of the American public".