The Supreme Court, Ideology, and the Decision to Cite or Borrow from Amicus Curiae Briefs

Scholars have sought to understand the dual characterization of Supreme Court justices as both legal and political actors. One way to further uncover this complexity is to assess how the justices engage with the interest groups that file amicus curiae or "friend-of-the-Court" briefs. Scholars have revealed that the justices often "borrow language" from these briefs in their opinions. However, much less often, they cite the amici. These two uses are distinct in that one is revealed to the reader while the other is not. So which interest groups do the justices decide to cite and which do they borrow language from? I find the justices borrow more language from ideologically similar interests, but that ideology plays a less central role in the decision to cite. Specifically, I find that the justices are less likely to cite briefs filed by ideologically overt interests, but this only extends to the most ideologically "extreme" groups. Further, the justices are not more likely to cite briefs filed by interests that are ideologically similar to their own preferences. These findings provide insight into how the justices balance policy and legitimacy goals.