I n Belgrade’s Pioneers Park, just across from the national assembly, a small crowd craned their necks to listen. One woman held aloft a placard reading “Love prevailed for the people and Serbia”. With a bouquet of media microphones in front of them, members of the Student List, the direct democracy movement that won an improbable but decisive victory in Sunday’s election, gathered under the trees.

Having spent days bathing in the euphoria of their unexpected triumph , the candidates’ focus was now clear: the cleaning up of the rotten institutions that had increasingly blighted the lives of Serbs over the 14 years of government by the populist leader Aleksandar Vučić and his Serbian Progressive party (SNS). They called for the dismissal of many senior law enforcement officials, among them the chiefs of the criminal police, the paramilitary gendarmerie and an anti-terrorism unit.

Student List supporters in Pioneers Park on Thursday, one with a placard saying ‘love prevailed for the people and Serbia’.…