 The difficulty, of course, is that the candidate non-law explanatory factors at issue (e.g., an ideological commitment to the Republican Party platform) are not plausible candidates for being legal norms, on any existing theory of the concept of law. Moreover, there are good reasons why social science treats the explanatory factors at issue as non-legal. For example, the moral and political attitudes invoked to explain decisions do not appear explicitly in the text of judicial opinions or in courts’ explicit rationales for reaching particular outcomes; they are often hidden and hard to detect, which makes them quite unlike any of the paradigm instances of legal norms, such as statutory provisions or judicial precedents. Finally, the legal/non-legal demarcation in empirical social science usually reflects more general explanatory premises about the psycho-social factors that account for behavior, well beyond the realm of the legal. The motivation for demarcating the legal/non-legal in essentially Hard Positivist terms is, for most social scientists, to effect an explanatory unification of legal phenomena with other political and social behavior.