Your definition of public interest as "public service announcements and emergency broadcasting" reflects an important aspect -- but just one aspect -- of the broader definition.
For example, the
Telecommunications Act of 1996 talks about:
...the obligation imposed upon them {broadcasters} under this Act to operate in the public interest and to afford reasonable opportunity for the discussion of conflicting views on issues of public importance.
and also says:
The Commission shall seek to promote the policies and purposes of this Act favoring diversity of media voices, vigorous economic competition, technological advancement, and promotion of the public interest, convenience, and necessity.
So the Act says that the public interest has to do with "afford{ing} a reasonable opportunity for the discussion of conflicting views on issues of public importance". And it furthermore says that the public interest has to do with things favoring "diversity" and "competition." So the Act itself contains examples which show that "the public interest" has a much broader definition than the overly narrow one you give.
I understand that the front-runner usually gets the lion's share of the coverage. But you must agree that it's curious how in this case, the front runner is getting the lion's share (Obama), and only ONE of the two runners-up (Hillary) is also getting a lot of coverage as well -- while the other the other runner-up (Edwards) is getting none at all. The media is reporting who won the gold and who won the bronze -- but not mentioning who won the silver.
More language from the Act below also seems to indicate a broad interpretation of "public interest":
(k) BROADCAST STATION RENEWAL PROCEDURES.
- (1) STANDARDS FOR RENEWAL. If the licensee of a broadcast station submits an application to the Commission for renewal of such license, the Commission shall grant the application if it finds, with respect to that station, during the preceding term of its license --
--- (A) the station has served the public interest, convenience, and necessity;
--- (B) there have been no serious violations by the licensee of this Act or the rules and regulations of the Commission; and
--- (C) there have been no other violations by the licensee of this Act or the rules and regulations of the Commission which, taken together, would constitute a pattern of abuse.
- (2) CONSEQUENCE OF FAILURE TO MEET STANDARD.--If any licensee of a broadcast station fails to meet the requirements of this subsection, the Commission may deny the application for renewal...
I would be curious anyone else can provide further examples of how "the public interest" is defined for the purposes of the Act.
Again, I would argue that at least MENTIONING the names of all three front runners in a three-way race for the Presidency would be part of any realistic definition. I would say that a systematic pattern of suppressing mention of the second-place winner in a Presidential primary, while always mentioning the third-place winner, constitutes
prima facie evidence of NOT serving "the public interest."