Ideology and the scope of judicial discretion: evidence from the federal district courts

Abstract This study examines how changes in judicial discretion influence ideological decision-making in the federal courts. Leveraging a pair of unanimous Supreme Court decisions that expanded district judges’ discretion to award attorney’s fees in patent litigation, we investigate whether this procedural reform led to substantive shifts in outcomes. Our differences-in-differences design reveals that conservative judges became significantly more likely to award fees after 2014 while more liberal ones did not. We observe no similar pattern in copyright cases, which experienced no comparable expansion of discretion. This patent-specific effect is driven by accused infringers seeking fees after defeating patent claims, consistent with conservative preferences for deterring frivolous litigation. Even unanimous, procedurally focused appellate rulings can lead to asymmetric ideological effects. These findings have implications for understanding how changes in discretionary authority—including the Court’s recent abandonment of Chevron deference—may systematically empower certain ideological preferences in the federal judiciary.