Chapter 1: Public Opinion and Counter-Attitudinal Voting.For decades, Supreme Court scholars have asked whether the Court is responsive to public opinion. Despite the importance of this question, however, unsettled and often contradictory theory combined with several empirical barriers have prevented scholars from answering it. This paper takes both theoretical and methodological steps to resolve this debate and argues that there is a direct relationship between public opinion and the choices justices make. Specifically I examine the conditions under which justices deviate from their ideologies to cast votes in line with the majority will. I find that justice are generally constrained by public opinion. However, the level of that constraint is conditional on the political environment. In short, justices are most responsive to public opinion when specific support is critical -- when they expect the probability their decision will be reversed or ignored to be high.Chapter 2: Public Opinion and Setting the Agenda When the U.S. Supreme Court decides which cases to hear it weighs a number of legal and policy considerations. While scholars understand a great deal about how each of these considerations factor into a justice's decision to grant a case, each term the Court faces this same set of considerations in hundreds of issue areas. Much less is understood about why the Court chooses to hear some issues and reject others. Adding to this literature, I argue that justices choose cases with public opinion in mind. Using a novel issue-specific and justice-specific measure of likely divergence from public opinion, I argue justices are forward-looking and select cases in which they are least likely to face pressure from public opinion to deviate from their ideological preferences at the merits stage. However, the relationship between public opinion and agenda setting is not direct. Rather, it is conditioned on the level of diffuse support the Court enjoys and the legal importance of the case. I also present some of the first systematic evidence that the Court is responsive to public issue salience when deciding what to decide.Chapter 3: Public Opinion and Stare Decisis.The U.S. Supreme Court, through the norm of stare decisis is responsible for setting the direction of the rule of law in the United States. However, to date the exploration of the Court's use of precedent in the literature has focused on internal ideological and institutional explanations, largely ignoring the potential for external constraint. Taking a step away from the traditional formulation of the Court's use of precedent, I explore the role of public opinion on the Court's treatment of its own precedent over time and in its majority opinions. I find no effect of public opinion on the decision to treat precedent even when conditioning the effect on the salience of the treated case, the Court's level of diffuse support, nor the level of threat posed by Congress. In short, while justices may be highly responsive to public opinion in the more conspicuous aspects of its decision-making, they seem to largely ignore public opinion when applying or creating legal rules.