Justice Roberto Barroso is one of the most influential judges in Latin America. In this paper, we challenge his theory of constitutional legitimacy. Barroso believes that the legitimacy of constitutional adjudication stems from three different functions performed by courts. First, courts play a counter-majoritarian role; second, a representative role. Although judges lack votes, they are better positioned than legislatures to interpret the will of the people because they are motivated by reason, rather than interests. Third, courts can break the political inertia and lead society. Although these powers should be used sparingly, courts can act as an “enlightened vanguard” and push history forward. We argue that none of these claims is justified and that Barroso’s own reasoning is no different in quality from the ordinary practice of elected politicians. Barroso’s theory of judicial legitimacy has facilitated an unprecedented politicization of adjudication and a serious threat.