From Go Left TV:

The collapse of mainstream media didn't happen overnight. It was the effort of years and years of work by the GOP, which culminated in the 1980's when Ronald Reagan repealed the Fairness Doctrine and loosened media ownership rules. As Mike Papantonio of Air America's Ring of Fire explains, this paved the way for media consolidation and the decline of the American press.

Part one:

Part two:

Part three: