I construct a simple theoretical model that incorporates the role of ideas and contested persuasion in processes of institutional change, specifically democratization. The model helps reconcile the view that extensions of the franchise in Western Europe tended to occur as a response to the threat of revolution with the view that these occurred based on a change of social values due to the Enlightenment. In particular, the model puts forward the argument that institutional changes become possible once ideological entrepreneurs –the carriers of an alternative worldview– win an ideological contest against the holders of traditional ideas so that the rest of society adopts their worldview, and a revolutionary threat becomes credible. The model shows that the preferences of the ideological entrepreneurs are key. A revolution takes place only if they prefer it to a peaceful transition. Also, the model predicts that actual revolutions occur only when the probability of them being successful is either low or high. Finally, the ideological benefits associated with adhering to a specific ideology affect whether institutional change is peaceful or not. A strong traditional ideology generating large psychological benefits of adhering to the status quo makes it more likely that democratization occurs through revolution. On the contrary, a strong alternative ideology favoring the extension of the franchise makes it more likely that democracy emerges but has an ambiguous effect on the likelihood of a revolution.