In the aftermath of the third wave of democratization, Latin American courts left behind decades of subservience, conservatism, and irrelevance to become central political players. They now serve as arbiters in struggles between the elected branches, and increasingly affirm fundamental rights. Indeed, some rulings champion highly controversial rights and have huge budgetary implications, sending shock waves across these new democracies. What explains this unprecedented expansion of judicial power? In trying to answer this fundamental question about the functioning of contemporary democracies, scholars of Latin America have developed a truly vibrant and theoretically dynamic body of work, one that makes essential contributions to our knowledge of judicial politics more generally. Some scholars emphasize the importance of formal judicial reforms initiated by politicians, which resulted in more autonomous and politically insulated courts. In so doing, they address a central puzzle in political science: under what conditions are politicians willing to accept limits to their power? Inspired by rational choice theory, other authors zoom in on the dynamics of inter-branch interactions, to arrive at a series of propositions about the type of political environment in which courts are more capable to assert their power. Whereas this approach focuses on the ability of judges to exercise power, a third line of scholarship looks at how ideas about the law and judicial role conceptions affect judges’ willingness to intervene in high-stakes political struggles, championing some values and interests at the expense of others. Finally, more recent work asks whether assertions of judicial power make a difference in terms of rights effectiveness. Understanding the consequences of judicial decisions is essential to establishing the extent to which more assertive courts are actually capable of transforming the world around them.