Bolivians began voting on Sunday, 17 August, in presidential and congressional elections that could end nearly two decades of rule by the left-wing Movement for Socialism. Polls opened at 8 a.m. and are due to close at 5 p.m., with the Supreme Electoral Tribunal expecting preliminary results covering about 80 % of ballots around 21:00 local time. Roughly 7.9 million citizens are eligible to choose a president, vice-president, 130 deputies, 36 senators and nine supra-state representatives. Pre-election surveys give businessman Samuel Doria Medina and former president Jorge “Tuto” Quiroga—both running on right-of-centre platforms—about 20 % support each, ahead of left-leaning senator Andrónico Rodríguez and the governing MAS’s Eduardo del Castillo. Unless a candidate secures more than 50 % of the vote, or 40 % with a 10-point margin, a run-off is scheduled for 19 October. The ballot takes place against a backdrop of an economic downturn marked by annual inflation near 25 %, fuel and dollar shortages and a fiscal deficit swollen by decades of subsidies. The crisis has deepened a rift inside MAS between President Luis Arce, who chose not to seek re-election, and former president Evo Morales. Morales, barred from running, urged supporters to cast null ballots but nonetheless turned out to vote. Security concerns flared after a small explosive device detonated at a school in Entre Ríos, Cochabamba, shortly before Rodríguez was due to cast his ballot. Interior officials said the blast caused no injuries or material damage; police are investigating and voting continued normally. The incident came three days after Arce replaced the military high command in an unannounced shake-up. More than 3,500 national and international observers are monitoring the vote. The new administration is due to take office on 8 November and will inherit the task of stabilising an economy that analysts say will require steep spending cuts and a credible plan to rebuild foreign-exchange reserves.