The majority opinion of the Supreme Court establishes precedent, but separate opinion writing affords the justices the ability to expound upon it or express their disagreement with the ruling or its logic. We broaden the exploration of separate opinion writing to consider how decisions and case features at the moment of granting cert shape justices’ decisions to engage in nonconsensual behavior. We also sharpen the focus on external actors to consider the nature of amici curiae. Through an empirical study of Supreme Court cases between 1986 and 1993, we find that aspects of the agenda-setting stage affect justices’ decisions at the litigation stage. In addition, we find that the number of briefs and the diversity of organized interests impacted by the case is particularly relevant to justices. The decision to write a separate opinion is the product of internal and external factors over the full course of a case’s history.
