Public interest lawyers often bring large-scale cases against government defendants for injunctive relief as class actions. Until recently, their class certification motions routinely succeeded, enabling plaintiffs to obtain sweeping remedies that have required fundamental reforms to government policies and practices. In recent years, however, the procedural law regulating the public interest class action has changed dramatically, with recurring doctrinal problems splitting the federal courts. Should a nascent trend against class certification continue, class action doctrine will soon present a formidable obstacle—possibly a barrier—to the successful prosecution of a sort of litigation that has produced innumerable changes to prisons, foster care systems, and other government agencies and services over the last fifty years. . . .