Judicious judging: The Effects of Political Division on Decision Making in the European Court of Justice

How do courts react to political debate? Their legitimacy hinges on their ability to uphold the law impervious to political pressure. The authority of the ruling follows from the court's reputation as apolitical. Politicization – understood as salient questions that divide stakeholders – threatens to erode this image. It imposes conflicting demands: Courts can prove their worth by solving questions for which there is a demand for a legal solution, but they risk their reputation in a politically divided environment.
Literature on judicial independence focuses on direct and explicit threats issued by the political branch. Arguments of legislative override typically predict that political division empowers the judiciary. In contrast, we argue that courts are sensitive even to the potential eruption of conflict because they value their diffuse legitimacy. Effective judicial policy making is thus a question of strategic timing.
To test our theory, we study the European Court of Justice. Known as the “dark horse of integration”, it is an independent court with political sway. Yet political considerations profoundly affects its decision making. We draw on unprecedented data mapping out the legal ambit of all preliminary cases relating to the Free movement of people throughout the history. We find that the Court holds back on the legal ambit of rulings, preferring to bolster its institutional authority, in times of political division. Reversely, it broadens the ambit when salience is high and conflict low. Thus, when salience and division combine, they null each other out; leaving traces only in the decision-making process.