Populist political parties are on the rise in Western Europe. Over the last two decades many Western European countries have experienced the surge of one or more populist political parties. In this paper we focus on the effects of such parties on mainstream parties. Our point of departure is Mudde’s (2004) proposition that we are witnessing a populist ‘Zeitgeist’ in Western Europe. Mudde argues that populism did not remain restricted to the political discourses of populist parties only, but affected mainstream political parties as well. This paper puts Mudde’s thesis to an empirical test. It aims to answer two main questions: (1) have mainstream political parties become more populist in the last two decades? (2) which characteristics of mainstream parties and populist parties affect the degree of populism of mainstream parties? The paper employs the results of a systematic content analysis of election manifestos of political parties in France, Germany, Italy, the Netherlands and the United Kingdom. The analyses do not provide support for Mudde’s thesis: the election manifestos of mainstream parties have not become more populist over the years. The paper is relevant for various reasons. First, the focus is not on the populist right only; the effect of the rise of populist parties on the left is also taken into account. Second, the paper tries to overcome the simple black-and-white perception of populism (in which political parties are described as either populist or not populist) and operationalizes populism as a continuum; parties can be more or less populist. Third, and most importantly, contrary to most inquiries into populism, the paper does not focus on populist parties only. Instead, its main purpose is to answer the question if mainstream parties have become more populist over the last two decades.
