(FORTUNE Magazine) – Possibly it was the time (about two hours) spent by your servant hovering over the transcript of oral arguments in The City of Cincinnati v. Discovery Network Inc. et al., an act put on recently by the U.S. Supreme Court and two lawyers from Ohio. Possibly it was the cost ($2.85 per page) of the transcript. But one way or another, we come away thinking this document is a beacon. It seems to be signaling that the Supremes are ready to reverse the broad hostility to commercial speech they have displayed in recent years. The Brethren have been all over the lot in trying to articulate the degree of protection afforded commercial speech (hereafter CS) by the First Amendment. State of play thus far: We know that CS has some rights, as evidenced by the fact that the Court keeps trying to say what they are. We also know that CS has fewer rights than ''political speech,'' as proved by the conceded ability of government to heavily regulate advertising, including even truthful advertising on behalf of legal products (like cigarettes). But you would think that after 50-odd years of thrashing around in this area, the fellows would have some principles they stick to. They really don't. Many of their opinions have minimized or disparaged the claims of commercial free speech. In 1942 ''purely commercial advertising'' was ruled to be entirely unprotected. In 1950 it was put down by Justice Hugo L. Black -- always a hawk on political speech -- in an opinion scoffing at the notion that merchants ''selling pots'' had constitutional rights. In 1986, in a case involving the right of Puerto Rico to regulate casino advertising, the Court evolved the theory that it obviously had that right, since it had the ''greater power'' to regulate casinos themselves. Since there is no constitutional bar to government regulation of any business, this theory bears the logical implication that government has a right to regulate any advertising. Along the way, however, Court majorities have occasionally worked hard at limiting regulation of commercial speech. The high-water mark for CS was reached around 1976-80, when the Burger Court signed off on several opinions featuring extensive rhetoric about consumers' legitimate interest in ''the free flow of commercial information.'' In the so-called Virginia Pharmacy case in 1976 (it concerned efforts by the state to ban advertising about drug prices), the Supremes made a rather forceful statement to the effect that free-speech values were not confined to politics: Information about commercial matters ''is indispensable to the proper allocation of resources in a free- enterprise system,'' and ''even if the First Amendment were thought to be primarily an instrument to enlighten public decision-making in a democracy, we could not say that the free flow of ((commercial)) information does not serve that goal.'' A fascinating feature of the other day's oral argument was that so much of $ the questioning went beyond even the Virginia Pharmacy rules. Several justices seemed to assume that, at least in some contexts, economic information might be just as important as political news. The Cincinnati case concerned those newsracks you see increasingly on city streets. Characterizing them as ugly, the city accepted that it could not bar those offering ordinary newspapers for sale but insisted it did have a right to evict racks used to distribute free commercial handbills -- most of them offering houses for sale. ''Why do you pick on commercial speech?'' Brother Scalia demanded of the lawyer for the city, then added: ''Of the important decisions I've made in my life, certainly buying a house is enormously important. I mean, much more important to me than the latest state of the war in Bosnia.'' Possibly he was tipping his hand less than we are optimistically assuming here; one can never be sure with professional arguers like the Brethren. But Scalia did seem to be saying rather clearly that the degree of protection afforded commercial speech depends on the importance to ordinary citizens of the information involved. It would appear to be the test commercial speakers have been waiting for.