Institutions and independence in models of judicial review

Regardless of whether judges make strategic decisions or choose to defer to the elected branches, two prior and basic questions remain. First, given that an autonomous judiciary runs the risk of usurping legislative power, what are the reasons for the existence of an independent judiciary? Second, given an autonomous judiciary, what accounts for the incidence (or lack thereof) of judicial invalidations of legitimate legislative enactments? These questions can be answered by using a stylized model of Congress-Supreme Court interaction. This model incorporates the seminal argument of William Landes and Richard Posner that interest groups serve as critical links between Congress and the Court. Central to the model is the conviction that groups, acting both in the legislative arena and as intermediaries between the branches of government, play a determining role in the separation-of-powers system.