Parens patriae
Definition
Parens patriae is a legal doctrine that lets a state, acting through its attorney general, sue on behalf of its residents as a group to protect an interest the state itself has, rather than requiring each affected resident to sue individually as a named plaintiff.
Why it matters
It gives state attorneys general standing to bring large-scale cases, like antitrust or consumer protection suits, on behalf of an entire state's population at once, far more efficient than residents filing thousands of separate individual claims and giving the state leverage no single resident would have alone.
Seen in the wild
Congress has written parens patriae authority directly into federal statutes, including the Clayton Act's antitrust provisions, which let a state attorney general sue in federal court on behalf of state residents harmed by an antitrust violation.1