The “Horizontal Effect” of Constitutional Rights

Among the most fundamental issues in constitutional law is the scope of application of individual rights provisions and, in particular, their reach into the private sphere. This issue is also currently one of the most important and hotly debated in comparative constitutional law, where it is known under the rubric of “vertical” and “horizontal effect.” These alternatives refer to whether constitutional rights regulate only the conduct of governmental actors in their dealings with private individuals (vertical) or also relations between private individuals (horizontal). In recent years, the horizontal position has been adopted to varying degrees, and after systematic scholarly and judicial debate, in Ireland, Canada, Germany, South Africa, and the European Union, among others. The issue has also been the topic of sustained debate in the United Kingdom following enactment of the Human Rights Act of 1998, for it remains an open and arguable question whether, and to what extent, the rights it protects will have horizontal as well as vertical effect. In the United States, by contrast, this fundamental issue has long been deemed fully and definitively resolved by a constitutional axiom: the state action doctrine. With the exception of the Thirteenth Amendment, both the text and authoritative precedent make clear that with respect to its individual rights provisions, the Constitution binds only governmental actors and not private individuals. End of story.