In the 1960's, FCC Chairman Newton Minow made a distinction between "the public interest" and "merely what interests the public."
It seems only fair and balanced to observe that Minow's old distinction reflected exactly the sort of controlling, condescending, nanny-state liberal attitude that makes government regulation such a bad idea. For how and why does a federal bureaucrat like Newton Minow get to decide what "the public interest" is? Why not respect the American people enough to let the public itself decide what interests it? Of course, this sort of objection depends on precisely the collapse of "the public interest" into "what happens to interest the public" that liberals object to. For the distinction between the two is itself liberal, as is the idea of a free press's and broadcast media's special responsibilities - "liberal" in the sense of being rooted in a professed concern for the common good over and above the preferences of individual citizens.
Which does indeed entail government's arrogating the power to decide what that common good is, it's true. On the other hand, the idea that at least government officials are elected, or appointed by elected representatives, and thus are somewhat accountable to the public they're deciding for. What appears to drive liberals most crazy about the right's conflation of "common good"/"public interest" with "what wins in the market" is the conviction that it's all a scam, that what the deregulation of industries like broadcasting, health care, and energy really amounts to is the subordination of the public's interests to the financial interests of large corporations. Which is, of course, all part of a very deep, serious national argument about the role and duties of government that America's having with itself right now.
And around and around it all goes.