Illegitimacy, Political Stability, and the Erosion of Alliances: Lessons from the End of Apartheid in South Africa*

Illegitimacy is widely identified as a cause of revolution and other forms of transformative political change, yet when and how it affects these processes is ambiguous. We examine when and how illegitimacy affects the stability of political regimes through a historical analysis of South Africa's National Party (NP) and its apartheid regime, which lasted from 1948 to 1994. Many scholars of South Africa identify the regime's illegitimacy as a catalyst for the end of apartheid. Yet, consistent with assertions that illegitimacy does not result in political instability, the NP maintained power for decades despite a domestic crisis of legitimacy and a global movement that decried the apartheid regime's illegitimacy. Interrogating this contradiction, we detail how the regime's illegitimacy contributed to the negotiated revolution in South Africa when it resulted in unacceptable costs for the allies that the government depended on for survival, motivating those allies to withdraw support. Building on our findings, we detail how turning attention to the ways that illegitimacy affects relationships with allies – rather than particular outcomes, such as revolution or state failure – allows us to account for variation in both when and how illegitimacy matters.