Does the demand for more direct democracy by populist parties have any implications for their internal decision-making? To answer this question, a novel large-scale research project analyses the 2017 candidate selection of all Bundestag parties, including the populist Alternative for Germany. Some 1,334 individual nominations of seven parties are compared using quantitative indicators along three dimensions of intra-party democracy (IPD): competition between aspirants for candidacy, inclusion of members and nomination-related communication. It shows that the AfD is living up to its promise of practising grassroots democracy: in all results it ranks at the top by a wide margin. A new populist organizational model seems to have emerged following neither the classic hierarchical and leader-oriented mode of many other European right-wing populist parties nor the delegate assembly mode typical of German parties. Our further development of IPD concepts, newly elaborated measuring methods and surprising empirical evidence improve the understanding of democratic decision-making in populist parties.