In Egypt and Tunisia, Islamist parties won by considerable and comparable margins (both the Muslim Brotherhood and Ennahda won roughly 37% of the vote) in each country’s first free and fair parliamentary elections following the deposition of its long-standing president in 2011. Explanations drawn from existing literature largely paint this outcome as a result of rational voting due to regime economic punishment and Islamic social service provision, or offer ideological explanations in which rhetoric invoking Islam had a unique and strong influence over Muslim voters. Though undoubtedly both rationalistic and ideological explanations account for why some individuals support Islamist parties, neither is fully satisfactory in explaining the electoral outcomes observed in 2011. Rationalist explanations fail to explain outcomes in Tunisia, where Islamist social provision simply did not exist after a massive crackdown on Ennahda in 1989. Similarly, ideological explanations do not suffice; a vast majority of citizens support the influence of Islamic tenets and a role for religion in politics (though they often disagree about the exact role) in representative survey data, which would suggest larger margins of victory for Islamist parties than observed. In addition, the countries have diverged significantly in their democratic consolidation since 2011, a divergence which has been driven by the behavior of leadership rather than a difference in electoral mandates. This paper is part of a larger dissertation project on the subject which moves beyond rational and ideological explanations for Islamist support, to an explanation that is rooted in the politics of repression and collective memory. The working theory of the dissertation is that repression of opposition groups by authoritarian regimes before 2011 matters for explaining post-2011 developments in Egypt and Tunisia. Both Islamist movements were significantly repressed by the previous Egyptian and Tunisian regimes, but when considered within their respective political contexts, their experiences of repression look different; in Egypt, Islamists were overwhelming targeted by repression while other opposition was not punished to the same extent, while in Tunisia, Islamists were highly repressed but within a context in which the majority of opposition was similarly stifled. I argue that by targeting certain groups in certain ways, these authoritarian regimes created different kinds of collective memory, which facilitates certain elite behaviors and creates certain patterns of mass support after the liberalization of each country’s political sphere. This paper outlines the dissertation’s theory and presents original survey, interview, and archival evidence supporting the argument from Tunisia.