Political Parties in Constitutional Theory

Abstract

In this paper, I first provide an idealized functional account of political parties and party systems. I argue that parties are difficult to regulate constitutionally because of their Janus-faced public-private character. The key function they perform, when functioning as they ought to function, is to facilitate a mutually responsive relationship between public policy and popular opinion by acting as an intermediary between a state and its people. They perform this intermediary function in a unique manner, because of their bi-directionality and their plenary character. When they perform this function effectively, political parties significantly reduce four key information and transaction costs which would otherwise make democratic governance impossible: political participation costs, voters’ information costs, policy packaging costs, and ally prediction costs. This idealised account helps us identify pathological parties and party-systems and ground four principles that constitutions should seek to optimise in relation to political parties. The second part of this paper outlines and defends these four principles. Here I argue that state constitutions: i. should guarantee maximum autonomy for the formation, organisation, and operation of political parties, moderated by the restrictions necessitated by their purpose of winning (a share in) state power (for fixed terms) in competitive elections by acting as intermediaries between the state and its people (the ‘purposive autonomy principle’); ii. should try to optimise the party system such that the total number of serious political parties is large enough to broadly represent every major ‘voter type’, but not so large that the information costs on judicious voters are too high (the ‘party system optimality principle’); iii. should ensure a separation of parties and the state (the ‘party-state separation principle’); and iv. should discourage the factionalization of political parties (the ‘anti-faction principle’). These political principles are drawn from the value of democracy itself. They are likely to bring real world political parties and party systems closer to their idealised form, thereby improving and deepening democratic governance. As such, they should—alongside other relevant political and constitutional norms—inform fundamental constitutional design choices.