Anyone who is for the fairness doctrine is trying to use unfair means to silence their adversary.
So it seems; that appears to be the motivation behind current Democratic efforts in Congress to reassert control of broadcast content.
But the original rationale for the Fairness Doctrine was really a case of creeping illogic.
The airwaves aren't like newspapers, for technical reasons. One town can have one newspaper, or it can have a dozen. The customer isn't forced to try to read all of them at once. However broadcast signals are different. A signal's broadcast bandwidth is tied closely to the bandwith of the signal it's transmitting. For simple voice, the signal bandwidth will be something around ten kilohertz - that's good enough for decent voice and music signals. Commercial radio signals in the US were once confined to amplitude modulated broadcasts in the "medium wave" band, from 520 to 1610 kilohertz. Allocating a bandwidth of 10 kilohertz to each station meant that 109 channels, absolute maximum, could be used. You don't want more than one station using the same frequency band, as listeners will pick up both at once, and the typical radio isn't smart enough to tell them apart.
In practice the US could have far more stations than that, because stations had limited ranges (though the limits varied with atmosperic conditions, primarily in the ionosphere - I picked up Radio Budapest one night on an old Philco radio). To artificially limit the range, broadcast power was limited by the FCC, the same government authority which allocated the frequency bands. The government got into the act for the same reason that it puts up "keep right" or "keep left" signs on the roads - without government direction, there was no way to keep multiple radio stations from interfering with each other's broadcasts.
The FCC ended up controlling a station's frequency band, its power and hours of operation (because of the much greater ranges at night, the FCC might require a station's power to be reduced at night, or the station might be required to go off the air entirely until the next day), and the directional properties of the broadcast. "Broadcast" is a bit of a misnomer; one of the multiple tower antennas in commercial station arrays shadows the signal, so that it doesn't go out in a full 360 degrees. That way the signal doesn't interfere with some other station on the same frequency in a particular direction.
From there, it was only a short conceptual jump to rationalize that the FCC should control content, as well as the technical aspects of a broadcast. Hence the rules requiring news breaks, even in exclusively music-broadcasting stations; limitations on the quantities of ads permitted; and bans on naughty words. The idea that news content should be controlled was only a tiny further step. But the implementation was fairly crafty; rather than censoring the broadcast, the station was required to add counter-propaganda. Of course what counted as something which must be balanced "fairly" was, and is, difficult to define. A news program could be broken up into "news", "editorials", and, oddly enough, "media events". At various times the Fairmess Doctrine might be considered to include one or more of those new sub-categories.
But what it all fundamentally came down to was that the government was trying to exert control over a broadcast, and that was always difficult to square with the First Amendment. Nevertheless, the Supreme Court managed to convince itself that the Fairness Doctrine was constitutional. (But never forget that the Supreme Court also found that Dredd Scott was still a slave - the Court can hardly be considered the end-all of American justice. Its record simply isn't good enough.) Oddly enough, it was the FCC itself that decided that its own power was too extreme, and impossible to square with the First Amendment, and it stopped enforcing the basic Fairness Doctrine about twenty years ago, although it didn't drop it completely until fifteen years later.
But the situation is even more complicated than that. If broadcast is actually a First Amendment issue, then it's not clear that any government agency (like the FCC) can charge fees for licensing. It should be as unconstitutional as a poll tax, or sales taxes on newspapers. That by itself could be a good reason for the FCC, and the courts, to agree that it's not a First Amendment issue after all.
