Scholars of Southeast Asian politics have emphasized contingent factors. The effect that the social classes might have on political change depends on the institutional starting point. Authoritarian regimes vary enormously in terms of their strength and their style of management. They can be based primarily on personal rule-by which a single leader rules arbitrarily according to his or her will-or they can be highly institutionalized, in which case the leader, or ruling group, abides by a set of formal or informal rules, including at times some form of elections, adoption of laws and decrees and parliamentary roles. Rules of conduct dictate the exercise of power of different elements within the state and guide relations with societal groups. In Indonesia, for instance, the type of authoritarian regime led to a highly institutionalized role of the military, elements of the bureaucracy and connections between the state and the business sector the proved quite resilient to pressures for change. Opposition groups, whether workers, students or other middle class groups, could not necessarily muster sufficient strength to mobilize effectively against the regime (Slater, 2008)