The law forbids (in the Court’s words) “knowingly stand[ing] on a ‘public way or sidewalk’ within 35 feet of an entrance or driveway to any place, other than a hospital, where abortions are performed,” with several exceptions:

(1) “persons entering or leaving such facility”; (2) “employees or agents of such facility acting within the scope of their employ­ment”; (3) “law enforcement, ambulance, firefighting, construction, utilities, public works and other municipal agents acting within the scope of their employment”; and (4) “persons using the public sidewalk or street right-of-way adjacent to such facility solely for the purpose of reaching a destination other than such facility.”

The majority (Chief Justice Roberts, joined by the four more liberal Justices, Justices Ginsburg, Breyer, Sotomayor, and Kagan) interpreted exception (2) as not allowing advocacy by clinic employees or agents, and thus concluded that this exception doesn’t make the law content- or viewpoint-based. And the majority also concluded that the fact the law was limited to abortion clinics doesn’t make it content-based: The law doesn’t draw any content distinctions on its face, didn’t “require[] ‘enforcement authorities’ to ‘examine the content of the message that is conveyed to determine whether’ a violation has occurred,” and was justified by concerns unrelated to the content of speech — concerns about “public safety, patient access to healthcare, and the unobstructed use of public sidewalks and roadways.”

Nonetheless, the majority held, the law is unconstitutionally overinclusive even though it is content-neutral. It bars communication in a traditional public forum (public sidewalks), including face-to-face conversation (and not just shouting across many yards) that is important to persuasion, and it does so even in many situations where there is no material threat of violence, congestion, obstruction, and the like. The government had many alternatives to these 35-foot-radius buffer zones, such as banning instances of obstruction, violence, or threat of violence, or even issuing injunctions following specific findings that a person or group has engaged in such misbehavior and less burdensome means for preventing misbehavior would likely ber ineffective. And the government hadn’t shown that such alternatives would do a poor job of protecting safety and clinic access.

To be sure, the majority said, the alternatives might be harder for the government to implement and enforce than a simple buffer zone — but that, the majority said, wasn’t enough:

As Captain Evans predicted in his legislative testimony, fixed buffer zones would “make our job so much easier.”

Of course they would. But that is not enough to satisfy the First Amendment. To meet the requirement of narrow tailoring, the government must demonstrate that alternative measures that burden substantially less speech would fail to achieve the government’s interests, not simply that the chosen route is easier. A painted line on the sidewalk is easy to enforce, but the prime objective of the First Amendment is not efficiency.

One question is whether McCullen might be seen as limiting Hill v. Colorado, a 2000 decision that upheld a Colorado law that forbade, within 100 feet of a medical facility entrance, “‘knowingly approach[ing]’ within eight feet of another person, without that person’s consent, ‘for the purpose of passing a leaflet or handbill to, displaying a sign to, or engaging in oral protest, education, or counseling with such other person.'” The Hill law was materially less restrictive, even of face-to-face conversations, and protected a form of personal privacy — freedom from close, directed approaches that intrude on one’s personal space — that is not implicated in this case. (I’m not sure how much weight this privacy interest should have, but the Hill majority said that it should have considerable weight, and the McCullen majority doesn’t deny that.) Still, as I argue in this post, the McCullen majority’s definition of content discrimination might make the statute in Hill unconstitutionally content-based.

For more on the debate between the majority and the concurrences about whether the law is content-based, see this post and this post.