Here's some good background and analysis from the Congressional Research Service (CRS) about the history and constitutional issues surrounding the Fairness Doctrine. (Matt Lasar has a summary of it over at Ars). The report, authored by CRS legislative attorney Kathleen Ann Ruane, does a nice job of outlining why, given heightened Supreme Court scrutiny of speech controls since the Red Lion days, the Fairness Doctrine would face serious constitutional scrutiny is it was re-instituted today:
It is possible that, in light of the proliferation of different types of media outlets since Red Lion, the Supreme Court will abandon the scarcity rationale for applying a lower standard of scrutiny to restrictions on broadcasters' speech. If the scarcity rationale is abandoned, the Court will likely begin to apply strict scrutiny to broadcaster speech restrictions like the Fairness Doctrine. Because the Supreme Court has struck down regulations similar to the Fairness Doctrine when applied to other types of media, it seems unlikely that the Fairness Doctrine would survive review under strict scrutiny.
Assuming that the Supreme Court would continue to apply intermediate scrutiny to government restrictions on broadcasters' speech, the Court would then need to decide whether the Fairness Doctrine withstands such scrutiny. The Court may choose to uphold Red Lion and the Fairness Doctrine under the principle of stare decisis, which requires courts to adhere to precedent. The Court also may choose to analyze a newly established Fairness Doctrine in light of evidence regarding its effects on speech that has developed since the Red Lion decision. To do so, it would have to answer two questions: (1) whether the Fairness Doctrine advances a substantial government interest, and (2) whether the doctrine is narrowly tailored to achieve that interest.
It does not appear that the Fairness Doctrine may be applied constitutionally to cable or satellite service providers. The Supreme Court has held that content-based restrictions on the speech of cable and satellite providers are subject to strict scrutiny. Strict scrutiny requires that the restriction at issue advance a compelling government interest and that the restriction be the least restrictive means of achieving that interest.
Content-based regulations of speech in the print media are accorded strict scrutiny. The Supreme Court has recognized that regulations similar to the Fairness Doctrine, when applied to the print media, are not constitutional. If regulations similar to the Fairness Doctrine could not withstand strict scrutiny when applied to the print media, it appears unlikely that similar regulations would withstand such scrutiny when applied to cable or satellite providers.
Complete report is embedded below as a Scribd document.