Patience with the president is running out: millions took to the streets on Sunday demanding Dilma Rousseff’s fall. This week a special commission to analyse the motion to impeach her should get cracking in Congress, after months of procedural wrangling. In theory, Ms Rousseff’s sin is dodgy government accounting. In practice, lawmakers will pass judgment on her mismanagement of the economy (doomed to contract by 4% or so for the second year running) and a corruption scandal in which her left-wing Workers’ Party (PT), and now her once-revered predecessor, Luiz Inácio Lula da Silva, look helplessly mired. Ominously, last week the PT’s main centrist ally gave itself 30 days to decide whether to exit the coalition. If it heeds calls from the (still mostly middle-class) anti-government throngs, odds against the president’s surviving until her term ends in 2018 will lengthen. She is in for a nerve-wracking month. So is Brazil.