Bolten will add zing to West Wing

He roars around Washington DC on a three-year-old Harley Davidson 'Fat Boy' motorcycle. He plays guitar in a rock band named Deficit Attention Disorder. Friends nicknamed him Bad Mitzvah in honour of his Jewish roots.

With a lifestyle like that, Joshua Bolten would seem a more likely candidate for a date with one of George W. Bush's twin daughters than one of the US president's most senior and trusted advisers.

Yet Mr Bolten's elevation to the position of White House chief of staff last week, to replace the long-serving Andy Card at Mr Bush's right hand, came as no surprise to those who have followed both his career and the principles of a Commander in Chief who values loyalty above all else.

'Bolten is cut from the same cloth as Card,' said Professor Paul Herrnson, director of the Centre for American Politics and Citizenship at Washington DC's University of Maryland.

'He's a different face and a new personality, but it's not like Bush is shaking things up or heading in any new direction.'

The son of an undercover CIA officer, Mr Bolten, 51, has quite a task ahead of him when he takes over from Mr Card, who was chief of staff for 51/2 years, on April 14.

As the president's most senior aide and strategist - and the second most powerful man in Washington, as some describe the role - it will be his responsibility to turn around the fortunes of a slumping administration mired in the Iraq war and under pressure at home on several fronts.

He has plenty of experience of the job, having served as Mr Card's deputy for two years before becoming White House budget director in 2003. And as policy director for Mr Bush's 2000 presidential election campaign, he built a good working knowledge of the issues, strategies and personnel important to his boss.

But critics charge that Mr Bush's decision to turn to the tried and tested, instead of seeking out fresh ideas and talent, as several senior Republicans have been demanding for months, is a missed opportunity.

'Simply rearranging the deck chairs on the Titanic by replacing Andy Card with Josh Bolten without a dramatic change in policy will not right this ship,' said Charles Schumer, a Democratic senator from New York.

Friends and former colleagues, however, of whom there are many, believe that Mr Bolten could be the perfect man for the job because of the knowledge he brings, both as an experienced politician and talented economist. Robert Hormats, vice-chairman of Goldman Sachs International and a Democrat who has worked with Mr Bolten, told the Houston Chronicle: 'He will reach out to a broader range of people to hear their point of view. The worst way to serve the president is to narrow the range of advice he is exposed to.'

His supporters also point to a man who is unafraid to speak his mind. After his promotion was announced last week, he wasted little time in announcing that he believed it was time for Mr Bush's treasury secretary, John Snow, to be replaced by a high-profile figure from Wall Street.

According to The New York Times, Mr Bolten believes that Mr Snow is no longer capable of delivering the administration's financial 'message' to the public, and that a new economic team is needed at the White House to tackle ballooning budgets and a record national debt of US$9 trillion.

Another popular Bolten anecdote relates to the terrorist attacks of September 11, 2001. With President Bush out of contact and amid confusion over whether more attacks were imminent, Vice-President Dick Cheney gave orders for the air force to shoot down any passenger jets heading for Washington and perceived to be a threat.

Mr Bolten pointed out to Mr Cheney that he did not have the authority to issue such a command, which could only come from the president or secretary of defence. That, Mr Bolten's supporters say, was the action of a man prepared to go out on a limb and unwilling to be used only as a cosmetic figurehead for others' policies.

A single man, Mr Bolten enjoys his slightly racy reputation. He is a regular on the Washington social scene and was pictured at a rally giving a ride to the actress Bo Derek after forming Bikers for Bush during the 2000 election campaign. He is also a talented 10-pin bowler and holds the unofficial Camp David all-comers' record of 207 out of 300.

Mr Bush referred to Mr Bolten's strong sense of humour as he announced the appointment, but raising the president's public approval ratings from an all-time low ahead of November's congressional elections will be a serious business. According to Professor Herrnson, that is exactly why Mr Bolten is there. 'Bush is very concerned about his popularity,' he said. 'He's starting to think about his legacy. If the Democrats take control of one of the houses of Congress, it could lead to all kinds of investigations. A lot of things swept under the rug would be out in the open.'