Ordinarily, a tax singling out the press for differential treatment is highly suspect, and creates a heavy burden of justification on the state. This is so, the Court explained in 1983, because such ''a powerful weapon'' to single out a small group carries with it a lessened political constraint than do those measures affecting a broader based constituency, and because ''differential treatment, unless justified by some special characteristic of the press, suggests that the goal of the regulation is not unrelated to suppression of expression.'' 34 The state's interest in raising revenue is not sufficient justification for differential treatment of the press. Moreover, the Court refused to adopt a rule permitting analysis of the ''effective burden'' imposed by a differential tax; even if the current effective tax burden could be measured and upheld, the threat of increasing the burden on the press might have ''censorial effects,'' and ''courts as institutions are poorly equipped to evaluate with precision the relative burdens of various methods of taxation.'' 35
Also difficult to justify is taxation that targets specific subgroups within a segment of the press for differential treatment. An Arkansas sales tax exemption for newspapers and for ''religious, professional, trade, and sports journals'' published within the state was struck down as an invalid content-based regulation of the press. 36 Entirely as a result of content, some magazines were treated less favorably than others. The general interest in raising revenue was again rejected as a ''compelling'' justification for such treatment, and the measure was viewed as not narrowly tailored to achieve other asserted state interests in encouraging ''fledgling'' publishers and in fostering communications.
The Court seemed to change course somewhat in 1991, upholding a state tax that discriminated among different components of the communications media, and proclaiming that ''differential taxation of speakers, even members of the press, does not implicate the First Amendment unless the tax is directed at, or presents the danger of suppressing, particular ideas.'' 37
The general principle that government may not impose a financial burden based on the content of speech underlay the Court's invalidation of New York's ''Son of Sam'' law, which provided that a criminal's income from publications describing his crime was to be placed in escrow and made available to victims of the crime. 38 While the Court recognized a compelling state interest in ensuring that criminals do not profit from their crimes, and in compensating crime victims, the law was not narrowly tailored to those ends. It applied only to income derived from speech, not to income from other sources, and it was significantly overinclusive because it reached a wide range of literature (e.g., the Confessions of Saint Augustine and Thoreau's Civil Disobedience) ''that did not enable a criminal to profit from his crime while a victim remains uncompensated.'' 39