Sao Paulo , Brazil ( CNN ) Throngs of protesters packed the streets of major Brazilian cities on Sunday , pushing for the impeachment of President Dilma Rousseff . Fueled by mounting anger over a corruption scandal that has implicated politicians in Rousseff 's party , demonstrators chanted `` Out with Dilma '' and `` Time for change . '' Police estimated that 275,000 demonstrators marched in Sao Paulo . A sea of protesters dressed in the green and yellow of the Brazilian flag used decades-old rallying cries to fire up their ranks , singing rock songs that date back to protests of the country 's one-time military dictatorship . It 's the second day of nationwide anti-government demonstrations in less than a month . And protesters vowed that it would n't be the last . There are a number of issues at play . One of the biggest : an investigation into a multimillion-dollar kickback scheme at the state-run oil company Petrobras . Most of the politicians accused in the investigation belong to Rousseff 's Workers Party and its allies . And during many of the years that the alleged corruption took place , Rousseff was the chairwoman of Petrobras . There has n't been any evidence she was involved with the scheme , and her supporters say the position is merely a figurehead . Rousseff has defended Brazilians ' right to protest and acknowledged the need to clean up corruption at Petrobras but denied any prior knowledge of the alleged kickback scheme . Brazilians are still outraged . Rousseff won re-election with just over 50 % of the votes in October , but her approval rating plummeted to 13 % after protests began last month . `` Many things have changed since the election , '' Janaina , a protester in Sao Paulo , said on Sunday , noting that even some people who voted for Rousseff were in the crowd . Some protesters said they 'd rather see Rousseff step down than push for impeachment , which could be difficult to push through without evidence tying the President directly to the corruption scandal . But Janaina said impeachment remained a realistic option . `` Yes , it has to be , '' she said . `` It 's our last hope . '' CNN 's Shasta Darlington reported from Sao Paulo . CNN 's Marilia Brocchetto , Catherine E. Shoichet and Jessica King contributed to this report .
Police reported that demonstrators marched in Sao Paulo . Many want President Dilma ##si to be impeached . A corruption scandal has affected politicians in her administration .