Mother's day brought us a new advertisement from the McCain campaign, featuring John McCain's mother, Roberta McCain, still sharp after 96 years.

The ad is a reminder of just how freaked out McCain's advisors are about his age, and how desperately they want to reassure the public that McCain is not too old to serve as president for four years. (If elected, McCain will turn 73 in his first year in office and will be 76 by the time the 2012 presidential campaign begins.)

Implicitly, the argument of this ad is that McCain comes from a good gene pool: his mom is in great shape at 96, so there's nothing to worry about. But there's a simple problem with that argument: like most (okay, all) people, John McCain has two parents.

If his campaign wants us to believe he is capable of serving a full term as president on the basis of his mother's health, it's relevant to ask about his father's health.

Sadly, John McCain's father passed away 27 years ago, in 1981. He was 70. (McCain's father, also named John, was a second-generation Admiral in the U.S. Navy, and like his son, attended the Naval Academy.)

McCain's age and fitness to serve as President are obviously a delicate subjects. That's probably why the McCain campaign is trying to get in front of the age issue with this advertisement. It's a smart move to be proactive, but I think they may be setting themselves up for a fall by using McCain's mother, simply because McCain is already almost two years older than his father was when his father passed away.

What they really need to do at some point is to open McCain's medical file completely. They probably won't want to do this, but the question about his health is a legitimate one. If the McCain campaign wants to win the election, they are going to have to satisfy voters that John McCain will be able to serve at least one full term as president at one hundred percent capacity. And to do that, nothing short of complete openness will do.