Outline This paper examines the entry of social movements in the political arena in the 21 st century to compete with regular political parties and institutions. Many of these movements have existed before but in contemporary times they brought new ideas and problems into the political agenda. The opening section sets the hypothesis that social movements diminish their chance of achieving their goals if they engage in the political marketplace with the use of violent and radical methods. Conversely, those that embrace the policy of non-violence and non-resistance are likely to succeed. Section 2 defines social movements and discusses why they come into being, how they grow, go into mainstream or decline. The next section names the violence-prone radical movements and describes how they engage in politics. It provides evidence that such social movements eventually dissolve, although some achieve some success. By way of comparison, Section 4 lists the peaceful movements that achieved their goals – and political prominence. The concluding remarks are found in Section 5. Introduction According to research on social movements, public dissatisfaction about mainstream politics grew before the turn of the 21st century because of the ineffective policy process. This gave rise to the formation of different social groups bent at first on calling national attention to their problems. They then evolved into political movements for social change that agitate for new values and policy frameworks. A social movement is then described as a process designed to facilitate the participation of ordinary people in politics and policymaking. The history of social movements reveals however that such participation of ordinary people in the body politic is often attended by radicalism. The new problems brought by social movements into the political agenda are also accompanied by radical and revolutionary ideas. The question then that this paper sought to address is: Does radicalism help social movements or do they need to tone down their political action and campaigns in order to attain their goals? Based on a case study of major social movements such as the labor and women’s movements, the paper takes the view that less radicalism helps social movements achieve their goals in a more desirable and longer-lasting way. When carried out with militancy and violence, on the other hand, such movements face restriction and eventual decline. Social Movements Tilly (2004: 36) defines social movements as a series of aggressive campaigns, threatening gestures, and displays of solidarity to impose the will of a social group on other people. In this view, social movements are a vehicle used by common people to achieve a desire to participate in politics and policymaking. In earlier centuries, most social movements fought for the interests of such groups as peasants and laborers, women, religious minorities, and blacks. The 20th century gave a new face to social movements such that their focus has extended to broader issues. Among the new social movements are the feminist movement, civil rights movement, the environmental movement, the peace movement, gay rights movement, and pro-choice movement. The creation of these social movements may have been triggered by an event or the emergence of a charismatic leader (Staggenborg, 2008: 6). An example of an initiating event is the public uproar caused by black woman Rosa Sparks who rode a whites-only bus in the US (Tarrow, 1994: 3). The chain reactio