Its called the Fairness Doctrine. Back in the 80's, Reagan opened up the radio airwaves to businesses and commercialism like they do on TV and since then, it went from a few hundred radio stations to tens of thousands. The radio band got so full, that satellite radio got started and XM and Sirius was born. It provided jobs for a LOT of people and still growing.
BUT some of those radio shows got so popular and using the freedom of speech, they can talk about what a terrible job that the democrats are doing and what bad unethical things they've done, well, the democrats didn't like it and now wants to get rid of those thorns in their sides like Rush Limbaugh, Sean Hannity, Bill O'Reilly, etc.
What people don't realize is that there is just as many radio hosts talking bad about the republicans too.
If you don't like it, change the station, but democrats wants all the stations to be liberal friendly like CNN, MSNBC, CBS, etc.
They are trying to cover up the unfairness of this law by calling it a "Fairness" doctrine.