ABSTRACT
Presidentialism has been long defined as a regime type based on the principle of separation of power. Institutionally, the metamorphosis of presidentialism was due to the adaptation of the United States (US) constitution of 1789 to the Latin American context, first executed by the Chilean constitution of 1833 and then followed by Argentine one of 1853. Most South American constitutionalists, led by Diego Portales and Juan Bautista Alberdi, considered that the major threat their new countries faced was anarchy rather than tyranny, because the difficulties of governing an uneducated population dispersed over a vast area far exceeded the dangers of a monarchical restoration. Concentrationist presidentialism involves the reduction of veto points in several or all of these dimensions, thus potentially increasing the capacity for presidential initiative, rapid response, and executive-driven decision making. The prominent role that Latin American presidents have played in crafting and implementing foreign policy is well established.
