ATV is screening Once Upon A Time In Arkansas (World, 10pm) tonight not because President Bill Clinton is on the verge of getting censured but basically let off by the Senate, but because there is still no chance of screening Riding The Tiger. The latter was pulled a fortnight ago when British distributors Channel 4 realised it had sold a programme to which it did not own the rights. Once Upon A Time In Arkansas was clearly made long before all the fuss over Mr Clinton's 'inappropriate' relationship with Monica Lewinsky, and manages to make sense of the Whitewater scandal which has dogged the president. The dramatic opening words describe the Whitewater affair as an inept conspiracy involving a group of old friends and adds, 'four have now gone to prison, one died by his own hand, and two live in the White House'. By now, everyone knows even Kenneth Starr realised this investigation would not result in anything nearly humiliating enough to Mr Clinton. Until quite recently though, most disinterested observers felt Mr Starr probably did have a point, but it was too complicated for mere non-lawyers to grasp. In this carefully researched documentary, made for the PBS series Frontline, the whole complicated mess is set out so well even the dimmest viewer can understand. Whether or not many will agree with the conclusion, or even that the Clintons really come out badly at all, is another matter. The undoubted heroine of the show is Susan McDougal, filmed from prison in Los Angeles, where she was serving a sentence for refusing to answer any of Mr Starr's questions. She is the wife of the jailed Jim McDougal, the businessman chum of the Clintons who had the idea to buy loads of land in Arkansas and to build lots of cheap housing units for working people to buy. Susan McDougal came up with the name 'Whitewater'. McDougal borrowed money from his own bank, Madison Guaranty, to pay for this deal, using a Byzantine maze of sham deals, at a time when Hillary Clinton was working as a lawyer for the bank. The best Mr Starr was ever likely to do was, if possible, to show the Clintons (especially Mrs Clinton, who drew up contracts for the bank) knew this was going on. The reporter unravels the plot mainly using the words of those involved, including the McDougals, and one of Mr Starr's prosecutors. Some are clearly still besotted with the Clintons, others detest them. All agree Jim McDougal is the man at the centre of the affair, and the Clintons cold-shouldered him following his disgrace. There are those who try to make this sound like a crime in itself, including the widow of a prominent Arkansas politician - who describes Mrs Clinton as Lady MacBeth - and McDougal. But it is not illegal to steer clear of friends who have fallen foul of the law, although admittedly it is not very loyal.