The Supreme Court's recent majority decision to grant a stay prohibiting the closed circuit broadcast of the proceedings of the Proposition 8 (gay marriage ban) trial in California was presented as being simply based upon the trial court's failure to follow its own guidelines for amending court rules. You have to read the dissent, however, to realize how political the majority had to have been to take the action they did. The dissent states that by six criteria the Supreme Court should have refused the stay.
Rather than address the merits of the case, I'll just say that the dissent appears to be more grounded in law and precedent. So why would the majority have ruled to keep the trial off the airwaves?
The Proposition 8 trial is a constitutional challenge against a California law passed by referendum which prohibits same-sex marriage. Its defenders are primarily Christian conservatives claiming to be protecting the historical definition and "sanctity of marriage". The challengers are led by gay rights activists bringing an equal protection argument against a law they believe is based on social bias.
Similarly, in 1925 the Scopes trial amounted to a constitutional challenge against a Tennessee law forbidding the teaching of evolution in school. Assisting in the prosecution of a teacher charged under the law, and by extension defending the law, was Williams Jennings Bryan, a three-time Democratic presidential nominee. The trial was highly publicized and was broadcast throughout the country. Bryan actually became a witness and set himself up (or was set up) as defender of the view that the Bible fully described man's creation. Although his testimony was legally meaningless and the judge terminated his cross-examination after only a couple of hours, the trial is partly remembered for the bombast of his testimony. Thirty years later the play "Inherit the Wind" was written based on the events of the Scopes trial.
The Supreme Court majority's decision to disallow broadcast of the Prop 8 trial should be seen as their cover of protection to anti-gay-marriage witnesses from any embarrassment they might suffer at the airing of their views at trial.