A generation ago, the police and press could do their job. The Rochdale boys' home was little better than a brothel and torture chamber in the 1960s. Rapists from as far as Sheffield would cross the Pennines to abuse the boys. Smith had a master key that let him into every room, and men now in middle age told MacKean in horrible detail what he did to them when they were children. Despite Rochdale having a small and tight elite, the police established that Smith administered fake medicals and corporal punishment — putting boys over his knee and beating their naked backsides. He smashed children's teeth out and forced them to have sex. The county constabulary was as keen to investigate as the town's detectives. It took over the inquiry to make sure that local dignitaries could not intervene.

Smith was so certain that the police would expose him, that he was weeping and popping Valium. Help came when he appealed to Jack McCann, Rochdale's Labour MP in the mid-1960s. Appalled that detectives were investigating a fellow politician, McCann went to the Director of Public Prosecutions. The law officer was equally appalled and killed the case. His "good name" cleared, Smith carried abusing into the 1980s, and widened his net to include young Liberal activists. After he showed his debt to McCann by ousting him in a dirty campaign, he had an MP's immunity. Channel 4 showed how Special Branch and MI5 protected him. When furious police officers went to the Rochdale Alternative Press and Private Eye, David Steel, the then Liberal leader, shrugged off their revelations.

The temptation here is to say there is something creepy about the Liberal Party. It professes to be feminist, but has no women MPs in prominent positions. The sex scandals that hit it with such regularity suggest its "liberalism" is of the porny, readers' wives, suburban swingers' variety, where any restrictions on sexual conduct, including limits on the age of consent, are oppressive impositions by the "squares".

Tempting though it is to damn the Lib Dems as the perverts' party, it is as much a mistake as damning Roman Catholicism as the paedophiles' faith. Padraig Reidy of Index on Censorship recently wrote about the dangers of missing the importance of hierarchical control in sexual abuse. Reidy is an atheist, but he is also an Irish atheist living in London, whose nose can pick up the whiff of British anti-Catholicism. Power, not faith, led to abuse, he wrote, and he was surely right. Whether they are celebrities at the BBC or priests in the Catholic Church, if you allow vicious men to become untouchable, you run the risk that they will touch up any woman or child they desire. If, as with Savile or Smith, you treat abusers as "national treasures", you run the additional risk that detectives or reporters will back away for fear of provoking the nation's wrath.

We say we have learned the lessons of the 1970s. But as I write politicians, at the instigation of celebrities, are paying a gruesome tribute to Cyril Smith, the ultimate celebrity politician. They are proposing a state-approved system of press regulation that will punish reporters who have committed no crime. Far from moving on, we are moving backwards.