The ‘mainstream’ in contemporary Europe: a bi-dimensional and operationalisable conceptualisation

The aim of this article is twofold. Firstly, it offers a new definition of 'mainstream'. Moving beyond understandings of the concept that focus exclusively on parties' alternation in power, or their ideology/message, the article's conceptualisation considers both supply and demand sides of politics. Hence, an attitudinal component to functional definitions is added. This implies that, to be called 'mainstream', certain attitudes must be shared by a majority of the public, and there must be no significant differences in their endorsement across political groups. Secondly, consideration is given to whether liberal-, social-democratic, and populist radical right (PRR) parties and attitudes meet this new reconceptualisation. While liberal- and, to a lesser extent, social-democratic parties and attitudes are indeed shown to be 'mainstream', the PRR is found to fall outside of the proposed definition, despite being 'established' on the supply side. The article concludes by underlining its wider theoretical implications.