Law is not magic, though many people confuse the two. It’s easy to see why: Both involve obscure and powerful verbal formulas that can change the world. But magic spells (which, alas, do not exist) let us fly about the housetops, change the weather, or summon spirits from the vasty deep. Law, when it works, does so only by changing the way people think. Those changes are not always for the better. While law can make our thoughts clearer, it can also spread or deepen confusion.

Even judges are not immune to this kind of confusion. One common pattern in Supreme Court opinions goes like this: (1) One court writes a decision with a perfectly ordinary phrase in it; (2) a judge in a different case seizes on the ordinary phrase and attributes to it a different meaning, until (3) the phrase comes to stand for something it never meant at the beginning.

The Supreme Court has a chance to sort out one such confusion this Monday when it hears the case of Reed v. Town of Gilbert. Though this case involves jargon, it’s a First Amendment case, and thus concerns those who don’t speak lawyer. So let’s understand the special term at issue. It is “content-based,” as in this formula: “Content-based restrictions on speech are presumptively unconstitutional."

It sounds great, but what does it mean? Taken literally—using words as normal people do—it means there can be no restrictions on any kind of speech. That’s because lawmakers and courts cannot assess free-speech questions without reading—that is, interpreting—the “content,” which the Oxford English Dictionary defines as “the things contained or treated of in a writing or document” of the message at issue. If they don’t, they can’t know that it is a restriction on “speech.” We know speech because it has content, that is, meaning in words. But in the caselaw, the words “content-based” are drifting ominously toward the wrong definition. The Court should clarify its meaning.

Reed concerns a nasty municipal squabble in the bustling small city of Gilbert, Arizona. (Gilbert was once literally a hayseed town, known as the "Hay Shipping Capital of the World," but today its population exceeds 200,000, making it the most populous “town” in the U.S.) The greater Gilbert area is home to Good News Community Church, a small congregation that worships in various rented locations. Obviously it’s important for the church to get the word out about where meeting is each week. Beyond that, its members say, they must obey Jesus’s Great Commission, Matthew 28:16-20 (“Go ye therefore, and teach all nations, baptizing them in the name of the Father, and of the Son, and of the Holy Ghost”). So the church has to put up signs near streets and roads announcing its services and welcoming newcomers.

The town says that GNCC’s signs are “qualifying event signs,” announcing a meeting of a “religious, charitable, community service, education, or other similar non-profit organization.” It’s perfectly happy for GNCC to put them up—as long as they are no larger than six square feet and are up only 12 hours before and one hour after the service. By contrast, it allows “Homeowners’ Association Event” signs to remain up for 30 days before and 48 hours after the event, “political signs” supporting candidates to remain up for four and a half months before an election and 15 days after, and “ideological signs” to remain up indefinitely. Each of these kinds of signs can also be larger than “qualifying event signs.”

The church should, and almost certainly will, win. The distinctions between different temporary signs are arbitrary, and the times and sizes for “qualifying events” are almost punitive. What’s important, though, is how it wins. The church argues that the sign code is “content-based.” That, they say, is “because enforcement officials must examine what a temporary sign says before they can determine which provision of the code to apply.” The Ninth Circuit called the sign code “content-neutral,” even though officials have to read the signs. That’s correct—properly read, the term “content-based” means based either on the viewpoint or the subject matter of the speech at issue.  

Courts that use the term “content-based” invariably cite to a 1972 case called Police Department v. Mosley, which struck down a Chicago ordinance that banned picketing of schools but made an exception for “peaceful picketing of any school involved in a labor dispute.” Justice Thurgood Marshall wrote for six justices that “above all else, the First Amendment means that government has no power to restrict expression because of its message, its ideas, its subject matter, or its content.” That kind of restriction, the Court has held, triggers a rule of “strict scrutiny” of any viewpoint (“no anti-government speech”) or subject-matter (“no religious speech”) regulations. It’s almost impossible for any law to survive “strict scrutiny,” and laws based—like Gilbert’s—on the need for aesthetic control of roadside signs are unlikely ever to do so.

Since Mosley, the phrase “content-based restriction” has become a shorthand phrase used by lawyers and courts. Until recently, it has meant a restriction or regulation of speech based on the “viewpoint” or the “subject matter” of the speech. The Gilbert code could be viewed as "subject matter" based—but it really isn't. "Meetings" is no more a subject matter than "marketing."  The proper way to decide this is that the ordinance is too restrictive, and discriminatory among speakers.

The slow degradation of “viewpoint-subject matter” rule is disconcerting. Justice Anthony Kennedy, in particular, has led the way in this area. In the unfortunate 2011 case of Sorrell v. IMS Health, Inc., he wrote (for six justices) that Vermont could not allow doctors to keep secret details about what drugs they prescribe from pharmaceutical companies seeking to sell them drugs. “The statute ... disfavors marketing, that is, speech with a particular content,” he wrote. The word “content” here has come unmoored. “Marketing” is not a “subject.” It’s an economic activity, to be regulated as needed by the specific market it involves. Kennedy’s foggy version of “content” will—very soon—take us to a place where government can’t regulate advertising at all. Already lower courts have applied the precedent to hold that cigarette companies have a First Amendment right to veto health-warning labels, and drug-company sales reps can encourage doctors to prescribe powerful drugs for unapproved uses.

The federal government is clearly worried that applying the Kennedy formulation to a sign case might gut the Highway Beautification Act of 1965. The act, as amended over the years, discriminates in size and area between kinds of signs, treating “service club signs,” for example, differently from signs advertising that the property they stand on is for sale. The government sides with GNCC in this case, but argues that, “so long as the government’s rationales for the regulation are related to its substantial interests in safety and aesthetics,” the standard should not be looser than strict scrutiny. It argues that the fatal label “content-based” should be reserved for laws that have the purpose or effect of regulating viewpoints or subject matter.

Burma-Shave signs were amusing when I was six, but on balance the highways look a lot better now than in the 1950s. Cluttered highways, however, will be the least of our problems if the Court muffs the “content-basis” question. Powerful forces are targeting all regulation of advertising. A world in which regulation of “marketing” is presumptively unconstitutional might look different, and worse, than the one we live in now.