BENIGNO AQUINO won the presidential election almost exactly a year ago, promising to clean up the deep-rooted corruption that flourished under Ferdinand and Imelda Marcos, among others. At last he has something to show for his efforts. On April 29th he forced the resignation of the ombudsman, Merceditas Gutierrez, who is the state's chief prosecutor of official corruption. Mr Aquino clearly regarded Mrs Gutierrez as the chief protector of official corruption, but only Congress has the power to dismiss an ombudsman.

So the president's congressional allies had her impeached. She was accused of failing to prosecute cases of alleged corruption within the administration of Mr Aquino's predecessor, Gloria Arroyo, who appointed her. Mrs Gutierrez denied any lapses, but resigned before the Senate could put her on trial.

It's the other lot that's corrupt

Mr Aquino campaigned under the slogan “If there's no corruption, there's no poverty,” which encapsulates the country's two main problems. Until recently he had made little progress. He tried to set up a commission to investigate corruption in the Arroyo administration, but was thwarted when the justices of the Supreme Court (most of them appointed by Mrs Arroyo) ruled that it was unfair to pick on just one group of people.

Mrs Arroyo herself denies any wrongdoing while president, but many of Mr Aquino's allies in Congress would like to prosecute her. This reflects the president's approach to fighting corruption, which is to punish the sins of the past rather than try to prevent crimes in future.

Mr Aquino has proposed few reforms to the system. His administration's reasoning is that the institutions for fighting corruption already exist; they just need to be put to work properly.

Recent history gives little reason to think his approach will succeed. Mrs Arroyo had her predecessor as president, Joseph Estrada, prosecuted for corruption, and the country's special court for trying graft cases, the Sandiganbayan, sentenced him to life in prison. Mrs Arroyo subsequently pardoned him. In last year's presidential election, Mr Estrada came second.

The institutions in which Mr Aquino puts his faith have brought dozens of cases against Imelda Marcos. None has succeeded in putting her behind bars.