This chapter explores how different proponents of the idea of a competition–democracy nexus envisaged the opertationalisation of the twin-goal of republican liberty and democracy through the protection of competitive markets as an institution of antipower. Various republican antitrust paradigms shared the idea that competitive markets operate as an institution of antipower that maximises liberty as non-domination and promotes republican democracy as long as they diffuse economic power polycentrically amongst a multitude of independent economic agents. Based on this assumption, all iterations of the competition–democracy nexus saw the role of legal rules and, most notably, competition law as securing a polycentric and deconcentrated market structure. The various republican antitrust paradigms also envisaged different ways through which competition law can guarantee and preserve polycentric competitive markets. These design approaches can be largely divided into two categories: situational and conduct-based structuralism.

This chapter analyses the decline of the concern about liberty as non-domination and the idea of a competition–democracy nexus following the ascent of the Chicago School and the rise of a More Economic Approach towards antitrust law on both sides of the Atlantic. It shows how the Chicago School not only challenged the economic foundations of the republican antitrust tradition but also put forward the consumer welfare standard as a versatile, principled framework to supersede the conception of republican liberty with a narrow negative notion of economic liberty as non-interference. The Chicago School thus shaped a laissez-faire approach to antitrust that seeks, in the first place, to preserve entrepreneurial liberty against state interference.