Conceptual accounts of separation of powers in constitutional theory have not seen a major update since Montesquieu proposed his theory of the tripartite institutional allocation of state power to the executive, legislative, and judicial branches. Three major developments have made this account wholly out of date. The first—and the oldest—of these developments was the rise of political parties that quickly became the real location of vast swathes of state power in way that completely scrambled the institutional division of power. Second, with the rise of the welfare state by the mid-twentieth century, the executive branch became extremely complex internally. In particular, the distinction between the political executive and the bureaucracy became very important. Finally, the growth of various accountability-seeking ‘fourth branch’ bodies, especially since the late twentieth century, put further pressure on the explanatory or normative capability of the traditional account.

This paper presents a conceptual framework for understanding the first of these developments, i.e. the rise of political parties in democracies, through a separation of powers lens. It does so by proposing a method of ascertaining the ‘party separation ratio’, a device that reveals the degree of separation between a particular party in a given regime. The higher the party separation ratio, less is the separation between a political party and the state at any given point in time. The ratio incorporates two key variables that determine the degree of a party’s separation from the state: (i) the minimum number of elections any party would need to win to capture electorally-distributed state power, and (ii) the actual number of (sufficiently powerful) state offices and institutions a given party actually controls at the relevant point in time. It ignores the form of power that the traditional theory puts so much to store by, and focusses instead on the extent of state power controlled by a particular political party. The account is then used to predict the ability of different constitutional arrangements to keep the party separation ratio in check or allow it to approach unity (i.e. a one-party state). It also hypothesises the circumstances under which a ruling party will be most likely to seek to entrench itself in the institutions of the state.

Professor Khaitan will also be speaking on Constitutionalising the Party at Jesus College on 18 October. Details for this event are available here:
talks.ox.ac.uk/talks/id/88f9b2ed-ac16-421e-ae6e-e861ca9d6364