AlterNet has an article out concerning a report issued by the Center for American Progress and the Free Press about why talk radio is dominated by right-wingers. This is a quote from that article:
The report contrasts the amount of right-wing talk -- nine out of every ten hours broadcast on talk-radio is exclusively conservative -- with a talk-radio audience that, according to Pew Research, identifies itself as follows: forty-three percent of regular talk radio listeners are conservative, while "23 percent identify as liberal and 30 percent as moderate." In other words, fewer than half of those listening to some of the most feverish voices on the right are themselves self-identified conservatives.
So why is this happening? According to the AlterNet article it is because of concentration of ownership of media outlets. The article notes that the report found that when media outlets are owned by women and minorities, such outlets are much less likely to just have right-wing talk radio. As the article noted:
An analysis of all 10,506 licensed commercial radio stations found that stations "owned by women, minorities, or local owners are statistically less likely to air conservative hosts or shows." In contrast, "stations controlled by group owners--those with stations in multiple markets or more than three stations in a single market--were statistically more likely to air conservative talk." Markets that aired both conservative and progressive programming were "less concentrated than the markets that aired only one type of programming and were more likely to be the markets that had female- and minority-owned stations."
What the article points out is that large media companies who own a lot of media outlets have a financial interest in promoting a political philosophy that worships the so-called "free market". It has a disincentive in promoting a political philosophy that looks at the airwaves as a public trust. This translates into supporting conservative talk radio even in markets where progressive talk radio has been a market success.
The article's authors also point out that, contrary to what right-wingers like Michelle Malkin are saying, the report does not call for a re-enforcement of the Fairness Doctrine. What it calls for is, from the viewpoint of media companies like Clear Channel and Fox, much more radical and that is limiting ownership of radio and television outlets. Such ownership was limited back in the 1950s and 1960s, but over the last three decades the FCC and the Congress have allowed companies like Clear Channel to buy up literally thousands of media outlets. If you are interested in the media, check out this Alternet Article.