Costa Rican election campaigns are experiencing important changes. Until recently, election campaigns and Election Day used to be considered as a “civic party”, celebration of democracy more than one particular candidate’s victory [Dabène, 1992]. Nevertheless, apathy seems to have characterized the last electoral campaigns. Actually, the decline of turnout and of campaigning participation, the crisis of traditional parties are manifest signs of this evolution. Although electoral campaigns tend to be less participative, they have never been so expensive. Moreover, campaigns are more and more present in the media and more professionalized. Besides, the regulation of campaigning has been dramatically reinforced, in particular the use of public funds and goods. Actually, Costa Rican election campaigns tend to share a lot of characteristics with what P. Norris calls “modern campaigning” [Norris, 1997]. However, the current changes are not uniform. Actually, the interest of this paper lies in an analysis of local changes related to macro-level evolution. Based on the observation of local campaigning in two popular barrios of San José, this paper will analyze the impact of macro-level changes on local campaigning and political activism. I will focus on strategies of rationalization that political parties try to apply at the local level; What form does these strategies take? How local activists are perceiving these strategies? and To what extent rationalization is affecting their capacity to reach resources essential to maintain their legitimacy in the barrio? Additionally, we will particularly look at the impact of the modernization of campaigning [Norris, 1997] on the structuration of the Costa Rican party system. We would make the hypothesis that the macro-level changes are actually affecting campaigning participation, and therefore also the political participation, in particular of the popular sectors.