Research Question: Has the informal nature of Iraq’s consociational system given it the flexibility to evolve through on-going negotiations, surviving the numerous challenges it has faced? Thesis Statement: This paper studies the evolution of Iraq’s political system since the first post-regime change elections of 2005, through four subsequent elections, seeking to explain its longevity. Arend Lijphart, the dominant intellectual in the study of consociationalism, argued that consociations based on informal rules “generally worked better”, because they were more flexible but also because they might indicate greater levels of trust between the political elites involved in negotiating the settlement. Iraq’s post-regime change political system, an informal consociation, has survived the numerous challenges it has faced: the steady reduction in voter turnout and the legitimacy of the system itself, the coercive challenges posed by the insurgency and civil war of 2004-2007 and the seizure of Mosul by the Islamic State in 2014, the mass Tishreen movement of 2019 and the violent contestation of the election results by key members of the governing elite in 2021-2. Despite these challenges, the informal consociational system has continued to deliver governments of national unity, binding a ruling elite together and to the Iraqi state. This paper examines how that system has changed to meet those challenges through intra-elite negotiations and continued to survive. Methodology: Data for this paper comes from a number of semi-structured elite interviews carried out across Iraq with key members of the country’s ruling elite from a number of different political parties. All the data gained during these interviews has been triangulated with the other interview data. Interviews data was then triangulated with research carried out on government documents, contemporaneous journalistic coverage and secondary sources. Conclusions or recommendations: Both the longevity and flexibility of Iraq’s informal consociational system raises troubling questions about the use of consociations in post-conflict settings. As Lijphart would have predicted, the system did create a unity of interest amongst senior politicians claiming to represent Iraq’s ethnic and religious communities. However, this elite pact did not stop widespread and extended violence, justified in the name of ethno-sectarian identity, it did not halt a steady decline in voter turnout and it has not prevented widespread politically sanctioned corruption from undermining the institutional coherence of the state.