On June 13, 2015, Manuela Carmena—a former judge and novice politician—stood in the ornate neo-gothic surroundings of Madrid’s Cibeles Palace. As she prepared to be invested as the city’s mayor, an enthusiastic crowd outside chanted “Si se puede” (Yes we can). After less than three months of political campaigning, Ahora Madrid (Madrid Now), the electoral alliance that Carmena headed, had pulled off a seemingly impossible political feat—ending twenty-four years of rule by Spain’s main center-right party in the country’s capital.