Who is going to determine what fair, balanced opposing opinion is? The left thinks that they are centrist and conservatives are racist, war mongering homophobes. The result would be an outright censorship of conservatives and the introduction of extreme leftists to balance their “moderate” views.
You have a good point there but then if they were rejected there would be law suit on top of law suit screaming discrimination under the same fairness doctrine. Could you see the SCJ ruling on that one especially if all the conservative radio and news programs got behind it to derail it in such a way. This may be a can of worms they really don’t want to open, at least I hope so.