AbstractUnamendability is often viewed as a ‘lock on the door’ that can keep enemies of constitutional democracy out, at least for a time. Unsurprisingly, it has also been invoked as a potential bulwark democratic backsliding. While it may not entirely thwart authoritarian populist takeovers, unamendability – including in the form of basic structure doctrines or constitutional identity review – is said to at least delay them, buy some time for defenders of constitutional democracy to resist, and clearly signal to the outside world (including supranational institutions such as the European Union) that foul play is afoot. This article questions such easy assumptions about the nature and operation of unamendability, both in general and in an authoritarian populist context in particular. It argues, based on the examples of India and Hungary, that unamendability is a tool either too ineffective to be deployed against authoritarian populists in power, even while courts may not have been fully captured, or one they are just as comfortable wielding as their opponents. For example, the Indian Supreme Court’s hitherto celebrated basic structure doctrine has been useless in the face of the court’s refusal to hear or decide key challenges against the government. Additionally, drawing on the Hungarian case, the article shows the dark side of constitutional identity review includes captured courts defending majoritarianism and exclusion in the name of a national identity perceived as under attack. In other words, doctrines of unamendability may quickly and subversively turn into instruments of entrenching the very authoritarian populist projects proponents of such doctrines abhor.