DAKAR, June 7 -- They came to power as a pair, the quiet president and the firebrand who could not run himself. Two years on, one has fired the other. President Bassirou Diomaye Faye has dismissed Ousmane Sonko, the prime minister who made his victory possible, and the man he removed now sits atop the one branch of government the president does not control.

Faye dissolved the government in late May and, on a live broadcast, named a new cabinet led by Ahmadou Al Aminou Mohamed Lo, a veteran economist he said had the expertise to steer Senegal out of its crippling debt. The choice was a statement in itself. Where Sonko is a movement, Lo is a balance sheet.

Sonko did not retreat into opposition, because he did not retreat at all. Pastef, h...