The Conditional Effectiveness of Legislative Threats: How Court Curbing Alters the Behavior of (Some) Supreme Court Justices

The separation-of-powers literature focuses on how the preferences of one branch constrain the behavior of its counterparts. Yet, in much of this work, scholars do not address how responsive behavior varies across particular members. Focusing on Court curbing legislation in Congress, we develop a model of heterogeneous responsiveness. Our theory identifies two distinct mechanisms that underpin responsiveness in judicial behavior, implying that the chief justice and the most moderate (swing) justice are more likely than their colleagues to adjust their behavior in response to external threats from Congress. We find that these two justices are significantly less likely to vote to invalidate legislation than their colleagues during periods of heightened Court curbing and provide evidence that distinct mechanisms shape their behaviors. In addition, we offer justice-specific evidence using a pre–post promotion analysis, demonstrating that Justice Rehnquist became responsive to Court curbing only after becoming chief justice. Our model highlights the micro-level underpinnings of judicial responsiveness to inter-institutional politics and, most broadly, speaks to the need for separation-of-powers models to differentiate the preferences of individual political actors when seeking to understand inter-institutional responsiveness.