This dissertation critiques the prevailing mainstream political science account of judicial decision making as personal preference driven and advocates, instead, an institutional-competence-based lens for analyzing judicial decision making. My methods are historical and interpretive. I demonstrate that the preference-driven view of how judges actually make decisions depends upon a model of legitimate judicial decision making as rigid rule following. In turn, I trace both this rulebound model of legitimate judicial decision making and political scientists’ fascination with revealing judicial departures from it to the conception of democracy as elite-managed, interest-group pluralism that predominated in the discipline in the late 1950s and early 1960s. In place of a rulebound model of legitimate judicial decision making, I advocate a model drawn from Legal Process Theory, a contemporaneous jurisprudential approach that understands appropriate judicial constraint in terms of judges’ respect for their institutional posture and the functions of other governing institutions in a broader, primarily democratic, process. Focusing on the midcentury jurisprudential thought of Lon Fuller and his influence on the canonical Legal Process thinkers Henry Hart and Albert Sacks, I demonstrate that the purposive but restrained style of judging at the heart of Legal Process Theory is the corollary of a robust, inclusive, and aspirational conception of democracy that arises from John Dewey’s vision of fallibilism as a moral framework powered by popular experience. If we prefer the Deweyan conception of democracy over elite-managed, interest-group pluralism as democracy, then we should choose the model of legitimate judicial decision making that supports that conception of democracy as our scholarly lens for bringing order to the unruly world of judicial behavior. A Legal Process model of legitimate judicial decision making also suggests important avenues for empirically investigating legal influence, as distinct from judges voting their ideological preferences.