ST. PAUL — Today's subject is geezerhood. Or, should John McCain be running for president at 72?

Call it an age-old question.

Should a guy who's 72 collect Social Security or try to fix it?

Should he be the one to take "the 3 a.m. call" — because he's up going to the bathroom anyway?

There is no shortage of opinions on the issue, or jokes for that matter, which explains why McCain often brings up the subject first. ("I'm so old," he told Jay Leno. "My Social Security number is 8.")

But for all the reasons why it's not a good idea for a person over 72 to become president — beginning with the fact that life expectancy for American males is 75.2 — there are plenty of good ones, too.

And you'll hear them all if you hang around long enough at the site of the 2008 Republican National Convention.

Beginning with a man I met yesterday after he spoke to the Utah delegation.

His name is Tom Kirk, he lives in Vail, Colo., and he leaves little doubt about who he'd prefer if you lined up John McCain and 47-year-old Barack Obama, or anyone else, for that matter, mano a mano.

"John McCain at 72 is in better shape than most men at 50," said Kirk. "I'd worry about everybody else before I'd worry about him."

Kirk met McCain 38 years ago this Christmas. There was no formal introduction. They were two of 46 men shoved into a holding cell in the Hoa Lo Prison — aka the Hanoi Hilton — in Hanoi, North Vietnam.

McCain, like Kirk, was a fighter pilot who had been taken prisoner by the Viet Cong in 1967. Both men had spent the bulk of their first three years in captivity, as the Vietnam War went on without them, in solitary confinement.

Finally having companionship, Kirk recalled, was the best Christmas gift ever. "We just hugged each other," he said, remembering the scene when the 46 prisoners of war were brought together. "It was unbelievable to be around others."

For the next four months while the prisoners were held together in that cell, he got to know John McCain about as well as one man can get to know another.

"He's extremely funny, extremely tough, extremely intelligent," said Kirk. "I've never known anyone who didn't adore him once they got to know him."

Kirk recounted McCain's struggles to simply stay alive after he ejected out of his fighter jet at 500 miles an hour.

He broke his right shoulder and right arm and threw his left arm out of its socket flailing around in the sky until his parachute automatically opened. Then he wrenched his left knee when he landed in a lake in the middle of Hanoi.