Le découpage électoral est marqué par le mythe du gerrymandering, ou du « charcutage électoral ». Gouvernements et majorités l’utiliseraient dans l’objectif d’établir une carte électorale favorable par la délimitation de circonscriptions visant produire des gains électoraux. Il serait un outil électoraliste utilisé à des fins partisanes. En France, cette perception prédomine notamment en raison du peu de travaux consacrés au découpage électoral qui est, pourtant, un objet important au sein de la littérature politiste internationale. La thèse propose une étude du découpage des circonscriptions législatives sous la Ve République selon deux axes. Le premier, relatif au processus, interroge le rôle et l’action du gouvernement. Grâce à une analyse pluridisciplinaire, il apparaît que le découpeur est soumis à de fortes contraintes, et que les députés y occupent un rôle majeur. Le second porte sur les conséquences des délimitations. Après l’élaboration d’une méthode permettant d’appréhender l’aspect politique des découpages, l’étude empirique – statistique et cartographique – établit que les circonscriptions sont découpées en fonction des députés – sortants –, avant d’être favorables aux partis politiques, ou à la majorité qui y procède. S’il apparaît également que les changements de délimitations ne produisent pas toujours les effets escomptés, ils disposent de conséquences structurelles qui se vérifient sur la compétition électorale. Sous la Ve République, les découpages électoraux peuvent être qualifiés d’interparlementaires et d’intrapartisans. In fine, ni le processus, ni les conséquences des découpages électoraux ne correspondent à sa représentation cognitive classique. / The myth of the gerrymandering overshadows the redistricting. Governments allegedly use it to draw a favorable electoral map aiming electoral profits. Thus, it is supposed to be an electioneering mechanism used for partisan motives. In France, few studies have been devoted to redistricting which is also an important object within the international political scientist literature. The thesis puts forward a study of the legislative redistricting under the Fifth Republic following two axes. The first one, the analysis of the policy process, questions the role and the actions of the government. Through a multidisciplinary analysis, it appears that the government is strongly constrained and that MPs have a main function. The second one relates to the consequences of redistricting. After developing a method to understand the politics of limits, the empirical study – statistical and cartographic – shows that districts are made according to deputies – incumbents –, before favoring political parties, or the majority making the redistricting. It also appears that if the constituency boundaries are not decisive, they still have structural consequences on the electoral competition. Under the Fifth Republic, redistricting can be described as interparliamentary and intrapartisan. To sum up, neither the redistricting process nor its electoral consequences match the "classic" cognitive representation of the redistricting.

Within the literature devoted to the study of political parties, scholars have recently directed more attention towards intraparty dynamics. The ‘party as a unitary actor’ assumption seems to have withered away in the last decades. The party is increasingly viewed as a heterogeneous entity, in which dissenting attitudes are frequent. Yet the causes of intraparty dissensions remain quite obscure. This dissertation aims at providing a better understanding of the causes of dissent within parties, especially within parliamentary party groups. <p><p>Intraparty conflicts, dissent or ‘voice’ phenomena have been studied through different literatures that have developed independently from each other: studies dealing with party factionalism, social-psychological and economic theories of organizations (e.g. Hirschman’s trilogy of exit, voice and loyalty), and legislative studies dealing with parliamentary party voting unity. The dissertation attempts to (re)conciliate these separate literatures, and shows how legislative studies, factionalism literature and theories of organizations can help to rethink the concept of dissent, and to grasp why parliamentarians are more or less likely to dissent from their party line. <p><p>The dissertation defines dissent in the parliamentary party as a two-dimensional concept, and operationalizes it as the MP’s frequency of disagreement with her/his party and the MP’s attitude of (non)loyalty in case of such disagreement. At the theoretical level, the dissertation draws on several theoretical approaches –institutional, rational and sociological– and formulates a broad set of hypotheses linking system-, party- and individual-level factors to these two dimensions of dissent. At the empirical level, the dissertation analyzes the causes of dissent within parliamentary parties in a comparative perspective. The analysis examines parliamentarians’ attitudes across 15 European national parliaments and tests the hypotheses formulated in the theoretical part by using the PARTIREP MP Survey dataset. <p><p>The results first show that, while European parliamentary parties are usually viewed as united blocks in terms of voting behavior, looking at MPs’ attitudes provides a more nuanced picture: European parliamentary parties show important variations in their MPs’ frequency of disagreement and attitudes of non-loyalty. Among the factors that explain these variations, both institutional (electoral rules, state structure, effective number of parties, intraparty organization) and sociological (gender, age, socialization, ideological preferences) factors need to be considered. In addition, the research shows that the two dimensions of dissent, though they are connected by a sequential relationship, should be studied distinctly, as different factors affect them respectively. The frequency of disagreement is best explained by the MP’s gender and previous elected office at a lower level than the national one, by the ideological distance between the MP and her/his party’s position in interaction with the party ‘family’, and by intraparty organizational factors (candidate selection procedures and EPO-PPO power balance). Non-loyalty depends more on the institutional structure (multilevel vs. unitary state, ENP) and on the candidate-centeredness of the electoral system; but is also affected by individual-level factors (age and length of incumbency) and by the party ‘family’. On the whole, by contrast to what is usually argued, ‘the party’ matters’ in determining the level of intraparty cohesion: the impact of intraparty organizational structure and party ideology or family is determinant, but more research is definitely needed in order to disentangle the ‘organizational’ vs. the ‘ideological’ effects.<p> / Doctorat en Sciences politiques et sociales / info:eu-repo/semantics/nonPublished