Malaysia's fifteenth general election (GE15) was a milestone in the country's democratization process, with three major coalitions contesting for national power after years of political instability. In this article, we investigate how Malaysia's cleavage structure - a central feature of Malaysia's prior authoritarian regime - shapes electoral competition in a newly competitive political environment. We find that the ethnic structure remains central to explaining party strategy and coalition behaviour in GE15, but that more democratic competition has increased the salience of regional differences - both between peninsular Malaysia and East Malaysia, and within peninsular Malaysia itself. Our analysis reveals the structural foundations of political competition in democratizing countries and contribute to the emerging literature on authoritarian legacies in such contexts.