Pseudo-classical Nonseparability and Mass Politics in Two-Party Systems Christopher Zorn 1 and Charles E. Smith 2 1 Department of Political Science, Pennsylvania State University, University Park, PA 2 Department of Political Science, University of Mississippi, Oxford, MS Abstract. We expand the substantive terrain of QI’s reach by illuminating a body of political theory that to date has been elaborated in strictly classical language and formalisms but has complex features that seem to merit generalizations of the problem outside the confines of classicality. The line of research, initiated by Fiorina in the 1980s, seeks to understand the origins and nature of party gover- nance in two-party political systems wherein voters cast partisan ballots in two contests, one that determines partisan control of the executive branch and another that determines party control of a legislature. We describe how research in this area evolved in the last two decades in directions that bring it now to the point where further elaboration and study seem natural in the more general formalis- tic and philosophical environments embraced in QI research. In the process, we find evidence that a restriction of a classical model that has animated work in the field appears violated in a form that leads one naturally to embrace the super- position principle. We then connect classical distinctions between separable and nonseparable preferences that are common in political science to their quantum and quantum-like counterparts in the QI literature, finding special affinity for a recently-introduced understanding of the distinction that provides a passageway into the boundary between fully quantum and fully classical views of the distinc- tion and thereby provides new leverage on existing work germane to the theory. 1 Introduction Among all of the academic specialties customarily identified as social sciences, politi- cal science is perhaps the greatest “debtor” discipline, in the sense that so many of the theories and methods and models put to the task of understanding politics are borrowed from scholars working in other fields. It is thus predictable that some of the latest and most promising theoretical and methodological innovations providing insight into the operation of politics are not native to political science. What is surprising is their foot- ing in quantum mechanics. Long thought in the main to be a theory with applications exclusive to the realm of the near-unobservably small, where probabilities rather than observable mechanics propagate in accordance with causal laws, the 21 st century is be- coming witness to an ever-growing export market for the quantum formalisms and the probability theory native to them. This paper follows that trend by illuminating a body of political theory that to date has been elaborated in strictly classical language and formalisms but has complex features that seem to merit generalizations of the problem outside the confines of strict classicality. D. Song et al. (Eds.): QI 2011, LNCS 7052, pp. 83–94, 2011. c  Springer-Verlag Berlin Heidelberg 2011