As law students frequently discover during exams, the law of standing is easy to state but hard to apply. The basic rules are simple and well-settled. Under Article III of the U.S. Constitution, in order to invoke federal jurisdiction, the plaintiff must demonstrate the existence of an "injury-in-fact" that is "legally cognizable," "fairly traceable" to the defendant, and capable of being "redressed" by the court. Each of the terms in quotation marks seems clear enough on the surface but has proved remarkably tricky in practice. The case law in the area has long been renowned for its inconsistency, and recent cases have often been unreceptive to environmental concerns.

The U.S. Supreme Court's latest foray into the morass of standing law was Friends of the Earth, Inc. v. Laidlaw Environmental Services (TOC), Inc. Laidlaw involved a citizen suit under the Clean Water Act (CWA), in which the plaintiffs attempted to obtain payment of civil penalties for pollution that had ceased before the district court's judgment. In finding a justiciable controversy, the Laidlaw Court accepted the standard formulations of standing and other justiciability doctrines, as well as the results of prior cases. Nevertheless, Laidlaw provides an important, helpful gloss on existing doctrine, smoothing away some of the more troublesome rough edges in previous opinions.