For decades, scholars have searched for data to show that Supreme Court justices are influenced not only by policy goals but also by legal considerations. Analyzing justices' agenda-setting decisions, we show that while justices are largely motivated by policy concerns, jurisprudential considerations can prevail over their policy goals. When policy goals and legal considerations collide, policy gives way. If legal considerations and policy goals align toward the same end, law liberates justices to pursue policy. In short, we find that at the intersection of law and politics, law is both a constraint on and an opportunity for justices.