Judicial transformation: The case of the Polish Constitutional Tribunal

Abstract Judicial transformation may result either from shifts in institutional context (prompting behavioral adjustment among incumbent judges) or changes in the composition of the bench (particularly through court-packing strategies that introduce new appointees). This article examines the case of the Polish Constitutional Court to evaluate which of these mechanisms better accounts for the controversial transformation of the court since late 2015. Drawing on data from constitutional abstract review decisions spanning 2003 to 2023, we analyze the behavior of distinct cohorts of judges. Our findings reveal a marked alignment with government positions following the October 2015 parliamentary elections, especially among judges appointed by the newly elected ruling party. The evidence suggests that the transformation is driven primarily by changes in judicial composition rather than by behavioral adaptation among pre-existing judges.