In a springtime thaw in the cold darkness of Mr Cheney’s relations with the outside world, he has conducted an introspective interview for the latest edition of Vanity Fair. This is a liberal-leaning magazine of the type he would not usually allow across the threshold — one recently leaked memo shows that he insists that televisions in hotel rooms are tuned only to Fox News.

Another sign of a counterintuitively nice side to the Vice-President can be found in the publication this month of a book written by Mary, his lesbian daughter. In Now It’s My Turn, she describes how she came out to her parents as a junior in high school, on a day when she skipped school, after breaking up with her first girlfriend, jumped a red light and crashed the family car.

Her mother burst into tears, worried that Ms Cheney would face a life of prejudice. But the first words from her father, she writes, “were exactly the ones that I wanted to hear, ‘You’re my daughter, and I love you, and I just want you to be happy’.” Ms Cheney said that people who had read the manuscript were genuinely surprised that she had “this close-knit, loving family”.

Mr Cheney’s approval ratings in the polls have recently sunk below 20 per cent, making this month’s record low of 32 per cent for President Bush look almost healthy.

Usually feared and respected in equal measure, he has this year encountered ridicule after accidentally shooting a 78-year-old Texas lawyer on a quail-hunting trip. It took him four days to explain what had happened to the public — and 36 hours even to tell Mr Bush.

Mr Cheney, 65, a White House Chief of Staff and Defence Secretary in previous administrations, was one of the architects of the war in Iraq and was profoundly affected by the September 11, 2001, attacks on America.

The article in Vanity Fair discloses that he travels with a chemical-biological suit at all times. When he gave his friend, Robin West, and his twin children a ride to the White House a couple of years ago, Mr Cheney referred to a lack of protective clothing for anyone else in the vehicle, saying: “Robin, there’s only one. You lose.”

The author of the article, Todd Purdum, describes him as the “Lord Voldemort” of the popular liberal imagination, referring to the evil character in the Harry Potter books. He quotes senior political and media figures who believe that Mr Cheney has hardened and changed since his relatively carefree days as an aide to President Ford in the 1970s. Some suggested that this might be related to the four heart attacks he has suffered.

In his interview, Mr Cheney responded: “Maybe because of my associations over the years, or because I came across as a reasonable guy, people have one view of me that was not necessarily an accurate reflection of my philosophy or my view of the world . . . My image might be better out there if I spent more time as a public figure trying to improve my image.”

Asked about his illness, he said: “I don’t even think about it most of the time. You do those things a prudent man would do and I live with it.”

His wife, Lynne, said: “If you’re looking for a change from one point to another, being Vice-President is sui generis . . . Its not quite like any other job.”

He is the first vice-president for more than a generation to promise not to run for the White House and, because Mr Bush is limited to two terms, there will be no incumbent in the next presidential election.

This lack of connection with voters is beginning to worry Republican strategists. “Maybe you could say that his (Cheney’s political antennae aren’t up as high as they would be if he were running for president himself,” said Andrew Card, the former White House Chief of Staff.

But Mr Cheney insisted: “I think we have created a system that works for this President and for me, in terms of my ability to be able to contribute and participate in the process.”

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