The Volokh Conspiracy
Mostly law professors | Sometimes contrarian | Often libertarian | Always independent
Judges to some extent tend to be reluctant to rely on their own moral or practical judgments. This tendency shouldn't be overstated, but neither should it be ignored. Thus, judges may defer to policy judgments underlying past judicial decisions, even if the decisions aren't strictly binding precedent.
And this tendency may turn from merely a legal rule that judges presumptively follow into an attitude-altering influence—judges may well conclude that they should assume that the precedents are morally or empirically sound, at least unless there's some strong reason to doubt their soundness. This is especially so because precedents are supposed to be carefully reasoned, persuasively written, and authored by people with high status. Thus, if the Supreme Court upholds a ban on bigoted epithets using justification J ("epithets are 'low-value speech' and can thus be punished"), future Justices may be persuaded by this principle, rather than just reluctantly deferring to it. And, as a result, they may eventually apply it more broadly to bans on other epithets or other assertedly low-value speech.
But what if the Court tries to prevent this broadening by explicitly adopting a limited justification J1, which is that "Only racially, sexually, and religiously bigoted epithets are 'low-value speech' and can thus be punished" ? This might reduce the risk of broadening: if a future Court accepts this entire principle as a guide, then it will be accepting the new exception's boundaries ("only racially, sexually, and religiously bigoted epithets are 'low-value speech"') as well as the exception itself ("[such] epithets … can thus be punished").
These two components, however, might have different degrees of attitude-altering force. A future Justice might find the "epithets may be punished" sub-principle to be more morally or pragmatically appealing than the "racially, sexually, and religiously bigoted epithets are special" sub-principle. The precedent would thus have persuaded future Courts that epithets should indeed be punishable—but not persuaded them to limit this to only a narrow class of epithets.
This danger might help explain why various Justices have refused to adopt new principles that lack well-defined, coherent limits. Thus, Cohen v. California reasoned that the proposed principle that profanity is unprotected but other offensive words remain protected "seems inherently boundless." Texas v. Johnson reasoned that "[t]o conclude that the government may permit designated symbols to be used to communicate only a limited set of messages would be to enter territory having no discernible or defensible boundaries." Hustler v. Falwell asserted that "[i]f it were possible by laying down a principled standard to separate [the attack on Jerry Falwell and his mother] from [traditional political cartoons], public discourse would probably suffer little or no harm," but concluded that "we doubt that there is any such standard, and we are quite sure that the pejorative description 'outrageous' does not supply one."
The Justices could have drawn boundaries and said "Profanities, flagburning, and parodies alleging grotesque sexual relationships are punishable because they are offensive, but other speech is protected even if it is offensive." But the apparent arbitrariness of these boundaries would likely have made them less influential in altering judges' attitudes. Even Justices who might want to draw such a line in one particular case might recognize that future Justices might find this line morally or pragmatically unappealing, and might thus accept the seemingly less arbitrary underlying principle (offensive speech may be punished because of its offensiveness), but reject the limitation to profanity, flagburning, and gross insult.
Of course, Justices considering a particular distinction may disagree on how "defensible," and thus influential, the distinction would be. Some Justices, for instance, might conclude that creating an exception for flagburning wouldn't lead to broader decisions later, because the flag "occupie[s] a unique position as the symbol of our Nation." Identifying the possibility of an attitude-altering slippery slope doesn't tell us how likely this slippage will be.
Nonetheless, such slippage is possible, and judges may want to be concerned about it when crafting their proposed tests. A particular judicial decision A might rest on a limited principle that on its own terms doesn't authorize a future decision B—for instance, the narrower justification J1 ("only racially, sexually, and religiously bigoted epithets are 'low-value speech' and can thus be punished") rather than the broader J ("epithets are 'low-value speech' and can thus be punished"). But this limitation might ultimately prove inadequate, and A might cause B in spite of the Justices' attempts to prevent such slippage. This possibility itself might sometimes be reason enough for the Justices to reject A, even if A—say, upholding a verdict against Hustler for publishing its outrageous attack on Falwell—might seem to them to be desirable on its own.