A dialogue was developed between Calabresi, Ackerman and Skach regarding the most successful separation of powers model. Calabresi argued in favor of USA’s presidential system, Ackerman supported constrained parliamentarism and Skach recognized the popularity of the semi-presidential.Recently, Gardbaum inspired by the work of Levinson/Pildes demonstrated that the separation/fusion between the executive-legislature depends on the political party and electoral system.That said,this article aims to revisit the original question posed by Calabresi on what elements render a constitution successful.It will argue that Constitutional law shall not rely on the conventional constitutional law wisdoms according to which a self-corrective force exits based on the rivalry between the 3 branches or based on the rivalry between political parties.This article aims to examine the constitutional settings that promote free/fair competition between state actors/political parties for the benefit of voters