There comes a moment, often unforeseen, which utterly changes how a political leader is regarded. Some rise to the occasion. Some fall. It happened to Bill Clinton, when suddenly there was news of his affair with Monica Lewinsky, a young White House intern. Despite being impeached, the former US president survived. He ended up more popular at the end of his presidency than at the beginning. It happened to Margaret Thatcher when Argentine forces invaded the Falkland islands. She fought and won a war on the other side of the world. And it happened to Angela Merkel, when she agreed that Germany “can do this” – welcoming a large number of refugees from the Middle East. It may now be happening in Britain to Prime Minister Boris Johnson. Mr Johnson’s appeal to British voters was always that he is different from other leaders, not afraid to break the mould, even if he also is known for a shambolic style and turbulent personal life. Now he is mired in allegations of corruption and incompetence, which raise questions about his judgement and suitability for office, from even within his own Conservative party. The word sleaze has attached itself to Conservative governments before. When John Major was prime minister in the 1990s, some MPs accepted money for asking questions in parliament. Mr Major stamped down hard and set up a new mechanism to improve ethical standards in the House of Commons. The only way to do this, he understood, was to bring in all the other political parties to clean up the reputation of parliament. In 2009, there was the parliamentary expenses scandal. MPs from both the governing Labour party and the Conservatives were punished for at times ridiculous and even fraudulent expenses claims. Some MPs were prosecuted and jailed. As with Mr Major in the 1990s, the Labour prime minister in 2009 Gordon Brown reacted, setting out to clean up the system and strengthen the rules. But now Mr Johnson has tried to do the opposite. He tried to change the regulatory system itself and get rid of the standards watchdog to stop one of his friends from being punished. Owen Paterson, the Conservative MP and former environment secretary, was severely censured by Kathryn Stone, the parliamentary standards commissioner for accepting £100,000 ($135,132) a year from private companies to lobby on their behalf. Mr Paterson is well liked in right-wing Conservative party circles. He likened those who wanted to ban fox hunting to Nazis. He was a climate change sceptic and cut funding for climate change projects. In 2013, tasked with reducing tuberculosis affecting farm animals, he presided over a cull of wild badgers which may have carried the disease, by having them shot. The cull failed. Mr Paterson claimed the failure wasn’t his own bad planning but because the “badgers are moving the goalposts”. British comedians ridiculed Mr Paterson as a government minister “outwitted by badgers”. When his lacklustre government career came to an end, Mr Paterson’s money making schemes led to the sleaze inquiry. But rather than accepting the verdict of the independent standards commissioner, Mr Johnson tried to force his own Conservative MPs to vote to save Mr Paterson. Those who were reluctant were warned they might lose the prime minister’s favour, lose their jobs and even lose government money for the areas they represented. Some resisted the pressure. Others voted against their consciences to do as they were told. The result was outrage from opposition parties, the media, voters and – most significantly – within the Conservative party itself. Some Conservative MPs refused to vote to rig the system. Those who did as the prime minister ordered were then exposed to the charge that they were sanctioning the underhand conduct of one of their friends, changing the rules to save a parliamentary crony. The outrage was so great that within 24 hours, Mr Johnson reversed himself. Mr Paterson resigned, and those Conservative MPs who voted to please the prime minister were left exposed. Needless to say, the blowback has been intense. Mr Major said Mr Johnson’s actions were “shameful and wrong” and that the Johnson government was “politically corrupt”. He suggested that he himself would find it difficult to vote for his own party if Mr Johnson remains prime minister. “I think the way the government handled that was shameful, wrong and unworthy of this or indeed any government,” he said. “It also had the effect of trashing the reputation of parliament” and was “profoundly un-Conservative… damaging at home and to our reputation overseas… There is a general whiff of ‘We are the masters now’ about their behaviour.” But the events of the past week are also part of a pattern of incompetence. Some suspect that Mr Johnson wanted to get rid of the parliamentary standards commissioner because he suspects she has on her agenda inquiries about Mr Johnson himself. Who paid for his expensive holidays and the refurbishment of his apartment in Downing Street? How is it that wealthy Conservative donors somehow end up in the House of Lords? And the big question: can Mr Johnson be trusted?