How Healthy Is John McCain?

It was the size of a dime and as thick as a nickel—a discolored blotch on John McCain's left temple. He didn't pay it much mind during the heat of the 2000 Republican primary campaign. But after losing the nomination to George W. Bush, the Arizona Senator found himself with time to spare. So as Bush celebrated victory, McCain headed to the National Naval Medical Center in Bethesda, Md., to have the spot checked out.

Less than three weeks later, McCain endured 5½ hours of surgery to remove a patch of skin including the blemish, roughly 5 cm (2 in.) wide. The diagnosis: Stage 2A melanoma, an invasive form of skin cancer that claims the lives of up to 34% of those diagnosed within 10 years. Doctors also made an incision down his left cheek to remove lymph nodes in his neck in case the cancer had spread; they found it had not. The surgery left a large scar, and for weeks McCain retreated from public view to recover.

Losing the G.O.P. nomination in 2000 gave McCain time to catch and treat the cancer at an early stage, which possibly saved his life. "If it was left alone, the risk was high that that melanoma would not just have become thicker but would also almost certainly have spread to the lymph nodes," says Dr. Jeffrey Lee, a cancer physician at the M.D. Anderson Cancer Center, who did not participate in McCain's care. "And the assumption would be that could occur within a period of a few months, if it hadn't happened already."

Eight years later, McCain at 71 finds himself on his way to another Republican Convention, and the questions about his health are no longer secondary to his political fortunes. If he were to win in November, he would become the oldest first-term President in U.S. history. To make the issue more pronounced, his likely opponent is young enough to be his son; at 46, Barack Obama hopes to become the fifth youngest President ever.

McCain's handlers know his age is both a strength and a weakness, one that his campaign is acutely sensitive about. Early this month, aides pounced on Obama's suggestion in a television interview that McCain was "losing his bearings as he pursues the nomination" by making negative attacks. Within hours, adviser Mark Salter had released a blistering memo saying the comment was a "not particularly clever" knock on McCain's age. "We have all become familiar with Senator Obama's new brand of politics," Salter concluded.

But if McCain intends to make his experience a plus with voters, he must also make sure that his health is at the very least not a negative. And so, after weeks of delay, the McCain campaign plans to deal with the issue later this month, with a release of his medical records and a briefing by his various doctors in Arizona, where he underwent the surgery. Though details are still being firmed up, the campaign says it expects to offer enough documents and medical opinions to lay to rest any concerns about the candidate's condition. "What you are going to find is that he is in good health," says Charlie Black, a senior adviser to the campaign.

On the trail, McCain likes to deflect questions about his age and health with jokes. "I'm older than dirt—more scars than Frankenstein," he says, often before telling a story about the spry antics of his still vibrant 96-year-old mother Roberta. At a recent meeting with newspaper editors in Washington, McCain pretended to fall asleep when asked about his age. Humor aside, the campaign has clearly decided that the candidate is his own best defense. "Obviously, I think there will be a greater observance of me," he said about his age while on a bus tour through Iowa last year. "Whether it has an impact or not will be directly related to my performance."