We already had the Fairness doctrine until 1987 when the F.C.C. lifted it. Thats when the big nationwide talk shows started. It also saved alot of radio stations from going under as A.M. radio struggled against the mostly music F.M.'s. Now that right sided talk radio crushes left sided talk radio in ratings teh left wants to put a stop to it. This article covers the topic pretty well.
http://www.heritage.org/research/regulation/em368.cfm