The paper aims to analyze from a theoretical standpoint under which conditions can populist attitudes successfully influence mainstream society and explain the resurgence of populist movements and parties in Europe during the current economic crisis through their attitudes and influence on mainstream political parties. To understand the nature of the success of populists and their attitudes in liberal democracies, it is useful to suggest how to approach the interaction between populist parties and movements and mainstream political subjects. This process could be seen in both ways as the radicalization of the mainstream and also as the mainstreaming of the extreme and radical organizations. The key variables suggested for analyzing the role of populist attitudes towards mainstream society would be the openness of the political environment to new populist movements, particular opportunity structures helping to the development of populism and strategies of mainstream parties in reaction to the populist rhetoric.
