Once celebrated as the only success story of the Arab Spring, Tunisia’s democracy and constitutionalism came under stress on the 25th of July of 2021. Since then, the government was sacked, the parliament was suspended, the judiciary was purged, and a new constitution was introduced disrupting the agreed-upon, and popularly- approved institutional balance of power. How did the birthplace of the Arab Spring end up there? Constitutional design is one explanation. The paper begins by reviewing prevailing explanations: "democracy not delivering", economic inequalities, failure of political Islam, rise of populism, polarization between secularists and Islamists, and support from regional powers, and end up suggesting that the design of the 2014 constitution should be taken seriously. The paper has two roles. First, critiquing the literature of constitutional design for its over-emphasis on the process itself of making the constitution, by showing how Tunisia’s inclusive and participatory process failed to sustain democracy. Secondly, to add up to existing explanations behind Tunisia’s presidential coup, by focusing on three suspect design choices: (1) the vague articulation of Article 80 on emergency powers which created several legal controversies - and as the paper will show, was deliberately left vague; (2) the multi-constituency selection mechanism of the Constitutional Court which, if there, would have evaded turning the whole constitutional crisis in Tunisia into a full-fledged presidential coup ; and (3) the logic of state structure and the semi-presidentialist system which was adopted in god faith in light of Tunisia's troubled history with authoritarian leadership, yet, disempowered the president after 2014 disallowing him to carry out his functions amid oft-happening parliamentary deadlock and rising post-revolutionary demands.