The Ramadan Affair has reopened the historical split over laïcité within the French left, but the dispute has found new grounds—about whether national identity is something fixed or evolving, about what place Muslims and immigrants have in the country’s future. These cleavages, which divide not only the French left but society in general, are something Emmanuel Macron had hoped to elude. But today, in the wake of the Ramadan Affair, Macron finds himself caught up in the return of this controversy over Islam and French identity. This time, it is neither the far right of Marine Le Pen’s National Front, nor those of the Gaullist right who emulate Sarkozy, who are winning, but an ex-Socialist who still claims to be on the left (he quit the party after the election). Valls may lack a political home for now, but he has signaled that he means to make identity—Islam vs. France—his main theme. If President Macron fails to pull the country out of its socio-economic doldrums, he will have to face a dangerously sharpened identity politics.