From what I was taught, The Fairness Doctrine (Equal Time) was for when a political candidate was brought in for an interview, a media outlet (TV or radio) had to offer a chance to the opposition to retort later. That is, get "equal (air) time". It really had to nothing to do with the leanings of the media in the aggregate.
http://www.museum.tv/archives/etv/E/htmlE/...equaltimeru.htm
The equal time, or more accurately, the equal opportunity provision of the Communications Act requires radio and television stations and cable systems which originate their own programming to treat legally qualified political candidates equally when it comes to selling or giving away air time. Simply put, a station which sells or gives one minute to Candidate A must sell or give the same amount of time with the same audience potential to all other candidates for the particular office.