I'll apologize now for the dramatic title. The 30% estimate is based on a number of assumptions, including the assumption he serves two terms, and that his risk is that of a typical white male of age 72. Although as I'll argue, his risk is probably marginally higher.
A debate is coming about whether Sarah Palin is qualified to be President. Before that debate even begins, however, we need to ask: how likely is it that Sarah Palin will have to succeed John McCain as President of the United States?
And so I'm diving into Age-Specific Mortality Rates, as provided by the CDC, to try to quantify the chances.
The CDC maintains a National Center for Health Statistics. Also very useful are survivor rates by age.
John McCain turns 72 today. (As trivia, McCain shares my birthday. Happy birthday, me.) As President, he would have some advantages - like the best possible medical care available; but he also has disadvantages, such as a hugely elevated risk of homicide, since nearly 10% of Presidents have been assassinated, as well as his history of melanoma.
Looking at the "Number of Survivors by age, out of 100,000 born alive, by race and Sex" data from the National Vital Statistics Reports, Vol 56, Number 9, for White Males:
Age 70: 72,531
Age 72: 68,193 [Estimation/Extrapolation]
Age 75: 61,683
Age 76: 58,871 [Estimation/Extrapolation]
Age 80: 47,622
I've added two estimates to the above numbers to capture McCain's age now, and McCain's age at the end of his first term, if he reaches it. This allows us to perform a simple calculation: if McCain is a typical white male, he has a 13.7% chance of dying in his first term. I'm sure McCain will have the world's most incredible medical care, which has to help his chances. But he has an extremely elevated risk of homicide (assassination), which hurts. He has also has high stress (President of the United States is clearly not a low-stress position, and elevated stress is statistically significant to mortality rates), and has his history of melanoma as a risk factor. McCain would be 80 years of age at the end of his second term.
All things being equal, McCain has a 30.2% chance of dying before he can complete two terms, and a 13.7% chance of death during his first term.
That assumes that McCain's risk is typical. While you have to give him some credit for longevity because of the doctors, I think the risk of assassination and his history with cancer probably swing his risk to being higher than average. Does the average person see a 1/3 chance that Sarah Palin will be President when they look at the Republican ticket? When I look at her mere 20 months in a significant office, I certainly want to make sure people know.
Clearly, part of being Vice-President is always readiness to assume the duties of the Presidency; however, McCain's advanced age means that much more consideration must be paid to the possibility of succession.