In recent years democracy in South America has been challenged by many socio-political crises. One of the reactions to this system strain is the movement of 'piqueteros' that emerged in Argentina mainly as a response to poverty, unemployment and inequality. The paper seeks to give some possible explanations for the rapid growth and present significance of this social movement. It also shows the structural and socio-political correlations that contributed to the success of the 'piqueteros', who without any institutional resources or political clout have become a powerful political actor. The case of the 'piqueteros' may be an example of an effective mobilization of the latent and excluded groups of society who despite their apparent passivity can constitute an important element of social change.