This paper argues that among the most consequential institutional variables affecting how constitutional orders operate are two relating to political parties. The first is the nature of the political party system (multiparty, two party, dominant party), which influences the actual separation of powers regardless of the form of government enshrined in the constitution. The second is the method political parties use to choose their candidates for chief executive in a general election. This helps to determine how easy or difficult it is for an “outsider” candidate posing a risk to the values of constitutional democracy to capture a major party and smooth a path to power. And yet, despite the importance of political parties to the constitutional order in these and other ways, they are rarely viewed as proper subjects for constitutional design. Although perhaps understandable from a historical perspective, this is mostly mistaken from a contemporary functional one.
Political parties are institutions that are integral to the functioning of constitutional democracy and should be conceptualized as public law institutions, alongside courts, executives, and legislatures. But political parties have been under-theorized in public law theory, which as a consequence possesses relatively few intellectual resources to understand, assess and propose a response to the current state of political party systems. A public theory of political parties can be built from two sources. First, it should be rooted legal materials and institutional practices, and offer an interpretive reconstruction of them which abstracts away from the particulars of how political party systems operate, to provide a critical standard which serves as a normative guide for assessing current practice. Second, it should be based on a careful rereading of the early constitutional theorists of parliamentary democracy – including Bagehot and Dicey.
In this paper, I will argue that democratic constitutions should seek to achieve two design objectives in relation to political parties:
(i) Protect the state from capture by a political party; and
(ii) Protect political parties from capture (by an autocratic leadership, wealthy donors or a narrow base).
These design objectives are drawn from the value of democracy itself. With respect to the first objective, a regime where the party and the state are sufficiently fused cannot be described as a democracy because the fundamental democratic tenet requiring genuine political competition is breached. Regarding the second objective, a political party that is captured by a narrow base, an autocratic leadership or wealthy donors—I will argue—is bad for democracy. The paper will then discuss some design solutions that, depending on the context, could be deployed towards these objectives.