Ce travail étudie la réaction des grands partis de gouvernement face au développement d’un clivage entre Écologie et Productivisme dans les démocraties occidentales. Pour ce faire, il croise la théorie des clivages et les théories de la compétition sur enjeux. L’hypothèse centrale de ce travail voudrait que ces partis neutralisent le nouveau clivage, en refusant d’accorder leur attention aux enjeux qui le constituent, en les cadrant de manière générale et liée aux clivages historiques et en prenant des positions qui n’impliquent pas le conflit avec leurs adversaires. L’opérationnalisation empirique de cette recherche combine la comparaison et les méthodes mixtes. Elle permet de montrer que les grands partis de gouvernement s’avèrent pour l’essentiel incapables de mener à bien leur stratégie de neutralisation : l’attention accordée au thème environnemental dans leurs programmes s’est accrue et ils ont dû mettre en avant de nouveaux enjeux environnementaux. La seule manière à travers laquelle ces partis parviennent à neutraliser le nouveau clivage consiste à adopter des positions qui n’impliquent pas le conflit. Toutefois, plusieurs facteurs expliquent les variations des réactions partisanes : l’agenda de l’environnement, la gravité du problème écologique, le positionnement sur l’axe gauche-Droite et les divisions internes. D’autres éléments ont un effet limité : les conditions économiques, la position institutionnelle du parti et la menace posée par les concurrents écologistes. Que les facteurs sociaux et environnementaux aient plus d’influence que les facteurs propres à la compétition politique rend d’autant plus pertinente une approche centrée sur les clivages. / This thesis studies how mainstream parties have reacted to a new cleavage dividing Environmentalism and Productivism in advanced industrial democracies. To do so, it associates cleavage theory and issue competition theories. The central hypothesis of this research is that mainstream parties should neutralize the new cleavage, by granting little attention to the diverse environmental issues that form the new cleavage, by framing those issues in relation to the historical cleavages on which they are funded, and by taking positions that imply no direct conflict with their opponents. The research design rests on comparison and mixed methods. The study concludes that big governing parties mostly fail to follow their ideal strategy. Their attention to the environmental theme has grown considerably over the last four decades, and they have had to deal with numerous new environmental issues that have no connection to the old cleavages. The only way these parties have been able to prevent the expansion of conflict is by taking consensual positions on those issues. Yet, many factors explain variations in parties’ reactions: the environmental agenda in the media and in social movements, the severity of environmental degradation, the left-Right position of parties and internal divisions. Other variables have limited effect: the macroeconomic situation, incumbency, and, more surprisingly, the threat posed by green party challengers do not seem to affect big governing parties’ politicization of the environment. The fact that social and environmental factors matter more than explanations based on party competition’s internal dynamics upholds a cleavage-Based approach.

A body of research has established the political relevance of Social Media (SM) platforms for populist parties, claiming that populist politicians utilize a ‘bypassing-strategy’. However, the rather reluctant employment of Facebook and Twitter by German citizens other than, for example, media professionals and politicians, raises questions of the utilization intention for public actors. Even though multiple scholars already indicated the necessity of research on the ‘embeddedness of digital tools’ in journalists’ routines (Jungherr, 2016: 374) such studies remain scarce. Therefore this study aims to shed light on how power is exercised by political actors through the use of SM within Chadwick’s (2017) hybrid media system. In order to do so it firstly examines the existence of references to the Twitter and Facebook pages of politicians of the German right-wing populist party AfD within the coverage of four German newspapers about the party during the final phase of the 2017 General Federal Election campaign. Secondly, by employing issue competition theory, issues and topics that three AfD politicians communicated about on their SM pages are compared with those that the party has been covered in relation to in newspaper articles. The findings of the quantitative content analysis on the newspaper articles showed only few cases in which AfD politicians’ SM statements were quoted. In regard to issue competition theory, the quantitative mapping of issues and topics in newspaper coverage about the AfD as well its politicians’ SM statements however, demonstrate prevailing similarities between the issues and topics that dominated the newspaper coverage about the party as well as its politicians SM pages. A thematic analysis on the latter found three themes that suggest a possible explanation for the few cases in which newspaper articles referenced SM statements: All three politicians used SM differently to promote, circulate and comment on issues and topics which influenced whether statements originated from the platform or from other contexts, such as rally events, tv debates, media article etc. These different types of content distributed and published on the politicians’ SM pages could be a possible explanation for the limited instances in which SM statements were quoted by newspaper articles. These findings suggest that the AfD did indeed pursued a bypassing strategy and employed SM platforms to directly communicate with its supporters. However, future studies should continue research on the embeddedness of SM statements in contexts other than campaigning times. Furthermore insights from qualitative interviews with politicians about their utilization strategies and journalists regarding their possible hesitance to quote politicians’ SM Statements, that may be grounded in professional standards, are necessary in order to obtain a more complete assessment of the role of SM for political actors in navigating the hybrid media system.