This chapter traces how the concern about negative economic liberty encoded in the consumer welfare standard and the laissez-faire antitrust approach coined by the Chicago School have transformed competition law on both sides of the Atlantic. It shows how this shift from republican to negative liberty as normative bedrock of competition law led to a recalibration of the role of legal presumptions, the standard of harm and the error–cost framework. It thus identifies the main parameters that drove the transformation of US and EU competition law from a republican antirust to a laissez-faire antitrust approach. This transfiguration displaced republican liberty as non-domination by a thinned-out understanding of negative liberty as non-interference as the ultimate goal of modern competition law and led to the disappearance of the idea of a competition–democracy nexus.