This study seeks to explain why the Tunisian and Egyptian revolutions mobilized different constituencies. Using original survey data, we establish that while participants in both revolutions prioritized economic concerns and corruption over civil and political freedoms, Tunisian revolutionaries were significantly younger and more diverse in class composition than the predominantly middle-aged and middle-class participants in the Egyptian Revolution. Tunisian revolutionaries were also less likely to be members of civil society associations and more likely to rely on the internet as their source of information during the revolution. We explain these differences by reference to disparate incumbent regime strategies for coping with similar structural pressures for state contraction and political reform, which created different patterns of societal grievance and opposition mobilizing structures in their wake.