Legislative Constraints on Executive Unilateralism in Separation of Powers Systems

Can legislatures effectively check unilateral executive power? One prominent and counterintuitive finding in previous work is that executives pursue unilateral strategies less often under divided government. We consider how legislatures’ ability to retaliate against executives influences unilateralism under inter-branch conflict, arguing that it is conditional on the policymaking capacity of legislatures. When polarization is high and majorities are marginal, executives are freer to act unilaterally given the difficulties legislatures have in statutorily responding to orders. Unilateralism is also more likely when legislatures lack non-statutory means of punishment, such as regulatory review. In one of the largest comparative analyses of executive unilateralism, we use a new dataset of 24,232 executive orders issued in the U.S. states between 1993-2013 to evaluate our theory and find strong support for our predictions. These results provide insights into how legislative policymaking capacity can influence the functioning of separation of powers systems.