Finding Law: Organized Interests and the Confinement of Executive Primacy

Filing written observations before the European Court of Justice (ECJ) is a key channel through which private actors, national governments, and the European Commission shape legal rules. While the Commission’s legal service has historically asserted interpretive primacy as “guardian of the Treaties,” recent scholarship highlights the influence of member states and private litigants. This article asks: under what conditions do private actors and governments displace the Commission as the main source of court rulemaking? Using newly available full-text observations from 2022–2025, I measure whose proposals—Commission, member states, or private parties—most closely match the Court’s operative part. Results indicate that the Commission’s presumed interpretive dominance no longer holds. Member states are nearly as likely as the Commission to propose rules closest to the Court’s reasoning, while private actors’ proposals are closest in over one-third of cases, though individual rights claimants are less successful.