Malaysia’s 2018 election saw the unexpected defeat of the United Malays National Organisation (UMNO) and the end of more than six decades of dominant party rule. Three core questions arise. How did the opposition finally overcome the extensive obstacles to achieve victory? What were anti-UMNO voters actually voting for? And finally, what do those answers imply for reform and democratization? We argue that Malaysia is actually comprised of four distinct identity-based polities, each with a unique electoral dynamic and vision for the country’s political future. Using this four arenas framework provides key insights into UMNO’s defeat, which was achieved by making inroads— largely through elite splits—in two previously impenetrable arenas. As one arena remains electorally pivotal, it exerts a disproportionately large influence on the new government’s reform agenda, as well as ensures the continued salience of identity politics.