Last month, the relationship between Senegal’s president and prime minister—which began as a genuine political partnership—ruptured when President Bassirou Diomaye Faye dismissed his former ally, Prime Minister Ousmane Sonko, over their differing approaches to dealing with the country’s debt. The rupture has exposed deeper tensions between pragmatic governance and reformist, anti-establishment populism and has left the country with two openly competing centers of power at a critical moment. As it unfolds, this rivalry is likely to produce a combination of policy stagnation and political volatility, whose effects threaten to ripple beyond Senegal’s borders. In that sense, Senegal has become a telling case study of what happens when a movement built in opposition confronts the constraints of power, with a president simultaneously negotiating with creditors while contending with a rival who commands both the legislature and the street. […]