Solicitor general influences justices.

In what follows, we examine whether the SG influences the votes justices cast and whether there are limits on the SG’s influence. We undertake this task in the context of the Supreme Court’s agenda-setting process. More specifically, we examine how justices respond to SG recommendations to grant or deny review to cases, focusing on cases where the SG files briefs at the behest of the Court and those (less frequent) cases where the SG files such briefs on her own cognition. We are aided in this endeavor by a research design that contains three critical components. First, we theorize justices’ ex ante preferences in each case. After controlling for these prior beliefs, we can then employ archival data to compare their actual votes to their expected votes and, thereby, detect influence. Second, by focusing primarily (though not exclusively) on cases where the SG has been forced to participate, we largely remove the possible selection effects that would arise from a strategic SG getting involved only in cases she expects to win. And, finally, we address features that may limit the amount of influence the SG wields.

We witness two important results. First, we find strong support for SG influence. Justices who completely disagree with the SG nevertheless follow her recommendations 35 percent of the time, a number we take to be powerful evidence of influence. Second, we discover that the SG’s influence is bounded by law. Justices of all ideological persuasions—even ideological allies—are significantly less likely to follow an SG recommendation that contradicts the weight of the law. This finding highlights the importance of law in judicial decision making and suggests that researchers should continue to look for evidence of legal influence elsewhere. In short, our results suggest that SGs will be most influential when they balance the often competing features of law and policy (Pacelle 2003; Wohlfarth 2009).