The private life and health of John McCain came under renewed scrutiny yesterday in two leading newspapers which are backing Barack Obama for president.

A hostile profile of Cindy McCain in The New York Times presented a sombre portrait of a lonely wife, ill at ease in Washington and lacking the support of her husband through miscarriages and an addiction to painkilling drugs.

The Washington Post explored the chances of McCain’s skin cancer recurring under the ominous headline, “Questions linger”. The paper commissioned biostatisticians at the National Cancer Institute to pore over the known facts about his illness and to check it against a national database of the survival rates of American cancer patients.

After a detour into alarmist speculation by a group of antiMcCain doctors putting the 72-year-old candidate’s chances of dying from melanoma at up to 60%, the article concluded that his risk of dying in office was in the low single digits.

Cindy McCain, 54, a beer distribution heiress with an estimated fortune of more than $100m, has been spared some of the close inspection of a candidate’s wife because of media fascination with Sarah Palin, her husband’s running mate. But The New York Times made up for it with an in-depth account which suggested that she and her husband lead almost totally separate lives.

It revealed that she preferred to spend time at her high-rise beach apartment on the Pacific coast rather than with her husband and that when they met up at their ranch in Sedona, Arizona, at weekends he would spend much of the time working. His friends in Washington, which she has called a “harsh town”, barely knew her, the article claimed.

When she arrived in the capital as McCain’s second wife, other congressional spouses snubbed her out of loyalty to Carol McCain, his first wife, who had survived a car crash which left her severely injured while he was a prisoner of war in Vietnam. Cindy’s relationship with McCain began while he was still married to Carol.

Cindy found McCain’s aides equally wary. “She seemed lonely,” said Lisa Boepple, a former chief of staff. But “she was John’s wife, so we didn’t really want to hang around with her”.

She retreated to Arizona, where she raised their three children and became involved in charities such as the land-mine-clearing Halo Trust favoured by Diana, Princess of Wales. On a trip to Bangladesh she adopted a daughter, Bridget, without telling her husband. He accepted her whole-heartedly, Cindy has said.

In an interview with Katie Couric on CBS News last week, McCain was asked why politicians, including Bill Clinton, were willing to risk their careers for infidelity.

He replied: “I don’t know and I don’t understand people’s personal lives . . . I want to be a good president and try to lead an honourable life . . . I’ve been an imperfect servant so I’m not judging.”

Asked the same question, Obama said: “I have no idea. The more I’m in public I don’t even want to pick my nose.”

McCain was not a cuddly person, friends told The New York Times. Cindy’s mother used to order her daughter’s birthday presents on his behalf.

Over the years Cindy suffered several miscarriages on her own while McCain was in Washington and he claimed that he did not know she had become addicted to painkillers in the 1990s – leading her to steal supplies from her own charity, the American Voluntary Medical Team.

Cindy blamed the addiction on back pain and pressure over a savings and loan scandal in 1989, when her husband was accused of improperly helping a leading donor. McCain said she had lost the receipts which could prove that they had paid for family holidays with the discredited businessman.

The New York Times also questioned Cindy’s account of a stroke in 2004. She claimed that it had left her temporarily unable to walk or speak and that she moved for four months to California to recover. But she appeared to be able to give interviews four days afterwards and also gave a speech in Arizona. “One month out I feel wonderful,” she told the audience.

Cindy has put her heart and soul into McCain’s quest for the White House, overcoming her discomfort with the campaign trail. Campaigning for president has provided them with the rare chance to spend more time together.

Yesterday she began campaigning solo at rallies for the first time in Pennsylvania – the only Democrat-voting state in 2004 that the McCain camp thinks it may be able to win, given the latest polls.

“She would walk on broken glass barefoot if it required her to do so in this campaign,” said Matt Salmon, a friend and former Arizona congressman.

If McCain wins, Cindy has already said that she has a role model for first lady in mind – Diana, who devoted herself to charity to escape the confines of her marital life.

Times Recommends

• 'New York has lost its edge'
• Copenhagen will fail – and quite right too
• More than 17,000 new underwater species found