Although the distinction between presidential, parliamentary and hybrid forms of government is fundamental to the study of democratic constitutions, it lacks a foundation in democratic theory. Empirical researchers do not define these forms in democratic terms, and normative theorists have largely neglected them. The article proposes a democratic conception of these forms and uses it to classify the constitutions of all 111 electoral democracies in 2024. The proposed theory and typology respond to various conceptual controversies and systematically link the classification of democracies to important issues in democratic and constitutional theory. Rather than relying on the ubiquitous principal-agent model, the article focuses on the democratic challenge of stabilizing the electoral authorization of the political executive in the face of unstable electoral and legislative majorities. Different constitutional responses to this challenge have important implications for democracy: different degrees of ‘depersonalization’ (Sean Ingham) of executive power and different constraints on legislative majority rule. The article highlights the unusual forms of democratic government in cases such as Australia, Bhutan, Guyana, Japan, Kiribati, Micronesia, Suriname and Switzerland, and has important implications for constitutional design and reform.