The paper presents the analysis of electoral political process in the Irkutsk region in the period from 2003 till 2015. This analysis is made with the help of electoral index of democracy and statistical data. The research findings explain the results of the regional governor elections in September 2015, which demonstrate the existence of competitive regional political system. The author examines the differences in electoral behavior of local population and identifies four types of municipalities with similar socio-economic and electoral indicators. Two factors determining high level of electoral competition in the Irkutsk region are described.