Separation of Powers: Legitimacy, not Liberty

Tara Ginnane published “Separation of Powers: Legitimacy, not Liberty” in Polity.

Abstract: The normative justification for separation of powers is canonically articulated in terms of liberty. However, critics of this justification claim that separation of powers either does not or is not necessary to protect liberty and therefore is obsolete. This article argues that separation of powers still has a valuable role to play in American politics, but not one articulable in terms of liberty. Instead, its value hinges on its potential to contribute to normative political legitimacy. I present the legitimacy model of separation of powers as an ideal to evaluate practice and assess proposed reforms. I build from political science work on conflictual constitutionalism to argue that the American separation of powers’ structure makes the branches differentially competent at identifying and considering certain types of reasons for actions. This makes it more likely that government decisions will be based on relevant reasons considered through appropriate procedures, which is a way to institutionalize a legitimacy-enhancing requirement that government treat those subject to its decisions according to an attitude that respects their autonomous capacities. The legitimacy model offers good theoretical reasons to affirm separation of powers’ potential value to contemporary political life.