When do electorally dominant parties lose power in democracies? Drawing on the experiences of India's states during the period of Indian National Congress dominance, we argue that single-party dominance is less likely to endure under two conditions: first, when one of the opposition parties possesses a longstanding and robust party organization and, second, when there is a single social cleavage dividing the political class into two main cleavage groups. Both conditions contribute to the demi...