This article aims to present four case studies of the different responses to governmental measures to fight the COVID-19 pandemic by supreme and constitutional courts, especially in cases of jurisdictions that have been facing democratic erosion. The spread of the COVID-19 pandemic demanded immediate public policies and other political decisions from the branches of government. Executive authorities were the main actors in effecting constitutional public health norms. The expectation was that they will abide by the rule of law in fulfilling (...) their duties; that has not been the case under governments that promoted democratic erosion. The different contexts of the threats posed to the constitutional democracies led populist and illiberal leaders to opportunistically either try to—and then be contained by courts—or effectively consolidate the expansion of powers under the conditions of the pandemic. Concentrating on four jurisdictions (the USA, Hungary, El Salvador, and Brazil), the article demonstrates that courts can effectively work as bulwarks against waves of democratic erosion, especially in situations of stress, as it was the case in the global COVID-19 pandemic. This hypothesis is also proven by episodes in which courts did not sufficiently operate to curb illiberalism because they were already captured. The analyses enable classifying the court’s responses to the COVID-19 executive measures in a threefold pattern: deferential, restrictive, and of forced capitulation. (shrink)