This chapter analyses how the ideal of republican liberty and the concept of a competition–democracy nexus have been implemented through concrete competition policy. To this end, the chapter looks at the interpretation and application of the three substantive pillars (i.e., the prohibition of anticompetitive agreements, the regulation of monopoly power, and the control of mergers) of competition law in the US until the 1970s and in the EU until the early 2000s. It describes how all three branches of competition law were interpreted in accordance with a republican conception of economic liberty as non-domination that perceived the very existence of concentrated economic power as an obstacle to economic freedom and democracy. This republican concern about liberty as non-domination as the central element of the competition–democracy nexus primarily manifested itself in the overarching policy goal of preserving a polycentric market structure as an institution of antipower. The republican antitrust tradition in the United States and in Europe built upon the structuralist approaches envisaged by various republican antitrust paradigms to operationalise the idea of a competition–democracy nexus that we discussed in the previous chapter.