That's what the liberals want to do. Companies sponsor radio shows (i.e. pay for advertising) that draw an audience. Radio stations play radio shows that draw an audience and draw sponsors. Conservative talk radio gathers a bigger audience and thus draws more sponsors. And liberals don't like the fact that they can't make the cut in talk radio, so what do they want to do? They want to legislate what radio shows a given radio station broadcasts because they can't offer anything that competes. So if Station A broadcasts Rush Limbaugh for three hours a day, five days a week, liberals want to force that same station to broadcast liberal whine for three hours a day, five days a week. It's what happens when your ideas are too weak to stand on their own merit. If you can't compete...legislate.
Read the article that got me all fired up here.