Why not liberal talk radio?

Many years ago there were several attempts to determine why liberal talk radio shows don't gain an audience. The conclusion was many-faceted. It was suggested that television "news" is liberal and meets the needs of liberals. It was also suggested that NPR and many music stations (music somehow being "liberal") were also favorites of liberals.
At any rate, there is movement afoot to restore the "fairness doctrine" to broadcasting. It is thought that this would then lead to the demise of conservative talk radio, or at least require an hour-by-hour "match" of one side to the other. Problem is, this didn't work during the early days of Rush Limbaugh. Alan Colmes had a 3-hour show that was strategically scheduled immediately following Rush. No one tuned in. By forcing "fairness" you will put the radio stations at an economic disadvantage, since the liberal hours will be worth virtually nothing in terms of ad sales. With Obama about to become President, conservative talk show producers are a tad nervous that he will stack the FCC with commissioners who will push "fairness," and liberals are hoping that this is the case.
I would prefer to see the FCC continue to examine and quickly mandate an increase in "localism" efforts by both TV and radio.
THAT makes sense, since we've strayed considerably from the mandates of our license: "To serve the needs, interests and convenience of the community" to which we are licensed.
Letting the "community" decide if a station is fulfilling that mandate may not be all that realistic in a community such as Tucson, where "apathy" is often a deciding factor in "decision making."