In a marathon session that started at 10AM on 11 May and finished just before 7AM the following day, Brazil’s federal senate voted by 55-22 in favour of initiating impeachment proceedings against President Dilma Rousseff. The margin of victory by the political opposition was wider than anticipated, and more than the two-thirds majority that will be needed to remove her from power permanently at the end of her impending impeachment trial. While Rousseff’s return to the presidency looks unlikely, much could happen during the six-month trial, and Vice-President Michel Temer, now the acting president, will face a series of severe challenges.