When Bill Clinton left the White House in 2001, he went straight on to America's lucrative after-dinner speaking circuit. George Bush senior retired to the family ranch in Texas at the end of his term of office eight years earlier. For Josiah Bartlet, life as the immediate past president of the United States promises to be a rather more taxing affair - as a student of philosophy and English literature at the University of Ireland. Bartlet is, of course, the fictional commander in chief in the hugely successful political drama The West Wing, which ends its seven-year run on US television screens next month. But the college plans are real and belong to Martin Sheen, the Hollywood actor who has portrayed the president for seven years and who feels, at 65, it is time he went back to school. 'I'm very serious about it,' said Sheen, who as a young man deliberately flunked his university entrance exams in his native Ohio in order to pursue a career in acting. Although once proud of having had no university education, he now says he 'gradually realised what I missed'. He admits he might prove a distraction to other students in Galway when he enrols as the 'oldest undergraduate' in the autumn. But he is sure he will fit in to student life in Ireland. '[It's] where my late mother came from and where I'm also a citizen,' he said. Sheen's decision to resume his studies at an age when most are happy to settle into retirement will come as no surprise to those who have followed the career of one of America's most unorthodox actors. One of the leading lights of Hollywood liberalism, Sheen has never been afraid to speak his mind, particularly over his strong opposition to President George W. Bush and his country's involvement in Iraq. It was never likely, therefore, that he would choose to slip away quietly once his character's tenure at the White House drew to a close. His post-West Wing career, in fact, might even have taken a turn into real-life politics had he listened to the overtures of Democratic Party officials in Ohio. After seven years of playing a principled president with morals and a conscience, Sheen was the perfect candidate for a run at a seat in the US Senate in this November's Congressional elections, they thought. Sheen turned them down. 'I'm just not qualified. You're mistaking celebrity for credibility.' It is a subject he has addressed in the past. In 1999, with The West Wing barely three episodes old but already earning plaudits for its radical and compelling new approach to political drama, Sheen was asked by the Cincinnati Enquirer if he had political ambitions of his own - a reasonable question given his regular attendance at various protest rallies and peace marches, and numerous related arrests. 'There's no way that I could be the president,' he said. 'You can't have a pacifist in the White House, and you can't have one in a White House on TV either. I'm an actor. This is what I do for a living.' Sheen's portrayal of Bartlet was widely acclaimed. He was 'equal parts Bill Clinton and Bobby Kennedy, without the exasperating testosterone difficulties', according to Tim Whitaker, a columnist for Philadelphia Weekly magazine. Yet although he maintained the character through a successful re-election campaign, the popularity and viewing figures of The West Wing, rather like George Bush's own second-term approval ratings, have tailed off, leading the NBC network to cancel the show this spring. David Bianculli, TV critic for the New York Daily News and National Public Radio, said that for the first two seasons, it was the perfect TV drama. 'It was funny, gripping, thought- provoking and even exciting,' he said. 'But in Bartlet's second term, The West Wing became a little less focused and substantially less satisfying. After (creator Aaron) Sorkin left the show, and even in the final year while he was there, it didn't crackle the way it used to.' Others believe that the show's demise, and the imminent cancellation of Commander in Chief, ABC's drama about the first female American president, after less than a year, mirrors the public's growing disillusionment with Washington politics. 'It's no small coincidence that the lifespan of The West Wing parallels almost exactly that of the Bush administration, which may account for why viewers had slowly but surely begun tuning out this kinder and gentler political universe: it no longer seemed steeped in reality,' says Whitaker. Ironically, viewing figures for the final series are up 20 per cent. The last episodes see Sheen back to his best as he winds down Bartlet's character to hand over the White House to his successor, and grieving at the funeral of his former chief of staff Leo McGarry, following the death in December of John Spencer, the actor who played him. 'Reality threw a tragic curve into the mix this year,' Bianculli said. 'The West Wing, in its final year, has returned to the fabulous form of its first. It's earned a renewal but isn't getting one.'