The starting point of this paper is the acknowledgement that the DNA of populism is democratic. At the same time, it may bring undemocratic or even counter-democratic consequences when it questions and contests liberalism and pluralism. This paper maps the key arguments on the relations between populism and authoritarianism, and discusses the risk of democratic backsliding as a result of authoritarian populism gaining power. This topic is critically important and growing urgent with the rising wave of populism across the Western world. Due to its chameleonic nature, populism (as a “thin-centered” or “empty-hearted” ideology) manifests itself in various (re)incarnations and intertwines with nationalism, libertarianism, and also radical left-wing ideas or any other ideology from across the wide political spectrum. First, the author reconstructs the historicity of populism as well as the most important ways of defining it. Second, he reflects on the major arguments about the consequences for democracy of populist politics. Finally, in conclusion, he discusses the threat of authoritarianism that populism brings to liberal democracy and democracy as such.