The Influence of the Solicitor General as Amicus Curiae on the Roberts Court, 2005-2014: A Research Note

In this article, we examine the influence of the Solicitor General (SG) as amicus curiae on Supreme Court decision making. We use the Supreme Court Database (SCDB) as well as original data on participation by the SG and other amici. Our data span the first ten terms of the Roberts Court: 2005 to 2014, inclusive. Our analysis employs logistic regression where the dependent variable is the ideological direction of the vote cast by each justice in each case (the "DIR" variable in the SCDB). To isolate the impact of the SG as amicus, we control for judicial ideology, the direction of the lower court decision under review, the participation of other amici, and whether the federal government is a party to the case. Our analysis shows that the influence of the Solicitor General as an amicus arguing for a liberal outcome exceeds that of the other variables in the model. The marginal effect of the Solicitor General as an amicus arguing for a conservative outcome is somewhat less, but still exceeds all other variables in the model except for the direction of the lower court decision. We also find that the SG's influence as amicus varies across the justices according to their ideological orientations. Liberal and moderate justices appear to be more influenced by the SG's amicus filings than do their more conservative colleagues.