This paper reviews regulatory efforts of the U.S. federal govern- ment to promote viewpoint diversity in broadcast media (radio, television, cable, and satellite) in the face of increasing concentration of ownership of such media, and the impact on such efforts of the free- doms of speech and press embodied in the First Amendment to the federal constitution. With respect to this issue, the regulatory work has been done overwhelmingly by the Federal Communications Commis- sion, operating under an act of Congress which has been amended from time to time to push the FCC in particular directions. The anti- trust laws are applicable to the media, but they have not been used explicitly to address the issue of viewpoint diversity. The regulations, under the statutory rubric of "the public interest," have broadly ad- dressed two dimensions of the media: programming content and concentration of media ownership. The dominant political theme of the last thirty years has been deregulation, but remnants of the earlier era persist and may be regaining favor, while the constitutional pa- rameters are unsettled in important respects. The FCC invoked the First Amendment along with market policies in abandoning most of its efforts to regulate content, but the courts have yet to fully endorse its view (adopted in 1987) that the constitution required it, and some statutory rules have remained on the books. Limiting the number of media outlets a particular person or enterprise can own has presented fewer First Amendment problems, and the FCC's deregulation has re- lied mostly on raising the permitted numbers; but it has been unable to persuade the courts that any particular formula of ownership limi- tation is rationally related to the overriding goal of viewpoint diversity, so that statutory rules which were meant to prod the agency into further deregulation have ironically remained as limitations.
Fisch, William B. "Plurality of Political Opinion and the Concentration of Media in the United States." American Journal of Comparative Law 58.- Supplement (2010): 505-532.