NOVEMBER 15th is a big date in Brazilian history books: on that day in 1889 a military coup overthrew emperor Dom Pedro II and established Brazil as a republic. This year it was significant for another reason. Despite the national holiday the president of the supreme court, Joaquim Barbosa, stayed at his desk and wrote warrants for the arrest of 12 of those convicted last year in the so-called “mensalão” case, several of them high-profile politicians with close links to the government. Eleven spent the weekend in jail; a 12th turned out to have fled to Italy several weeks before. But just what was the mensalão? The word, a Portuguese neologism roughly meaning “big monthly stipend” was coined to describe clandestine payments made by the Workers’ Party (PT), which won the presidency in 2003, to congressional allies in return for support for its legislative agenda. The scandal broke in 2005 when the president of an allied party claimed in a newspaper interview that the PT was paying several congressmen 30,000 reais a month (around $12,000 at the time). The money was said to have come from the public purse via fake advertising contracts signed by state-owned companies with corrupt advertising firms. The scandal was one of many that broke in quick succession, with others involving allegations that the state-run postal system had accepted bribes for contracts and that the PT had been extorting money from illegal-betting rings in Rio de Janeiro. Overlapping congressional inquiries ended up accusing 18 congressmen of involvement in the vote-buying scheme. The biggest name among them was José Dirceu (pictured right), who had been chief of staff to the president, Luiz Inácio Lula da Silva, until forced by the scandal to step down.

Holders of high office in Brazil are entitled to have cases against them heard by higher courts, and with so many of the mensaleiros in Congress, that meant that only the supreme court had jurisdiction. Not until mid-2012 did it get around to trying the mensalão; by the end of the year, 25 of the 40 defendants had been found guilty of crimes including bribery, money laundering, misuse of public funds and conspiracy. But Brazil’s legal system is a loophole-ridden oddity, allowing appeals even against supreme-court rulings. In September, 12 of the defendants successfully argued that they should be granted fresh trials next year for those charges where at least four judges had voted for acquittal. With two new judges on the 11-member court, those verdicts may be overturned. But in recent days the supreme court dismissed another flurry of arcane appeals seeking to clarify supposed omissions or contradictions in the sentencing. With almost all the verdicts now definitive, there was nothing to keep the defendants out of jail.

Accusations of political graft are ten-a-penny in Brazil. But the mensalão was different. The revelation of such widespread and organised vote-buying in Congress seemed to strike at the heart of Brazil’s still-young democracy. And that the culprit was the PT, which had campaigned on an anti-graft platform, made it worse. For a while Lula himself looked likely to be brought down, but without evidence that he was complicit in the scheme he managed to hang on and then bounce back. He was re-elected president the following year and finished his second term so popular that he was able to get a political neophyte, Dilma Rousseff, elected as his successor. That powerful and well-connected criminals have finally ended up behind bars is a milestone in Brazil’s slow progress towards the ideal of equality before the law.