McCain and his advisors are poo-pooing the idea that Governor Palin lacks the experience to be Vice President, or is unqualified to step into the role of commander-in-chief at a moments notice, praising her as "exceptionally talented and intelligent and that he felt she would be able to be educated quickly." Moreover, they point out that she will have plenty of time to learn the ropes, and under the tutelage of the experienced and sage President McCain:
“She’s going to learn national security at the foot of the master for the next four years, and most doctors think that he’ll be around at least that long,” said Charlie Black, one of Mr. McCain’s top advisers, making light of concerns about Mr. McCain’s health, which Mr. McCain’s doctors reported as excellent in May.
If you want to put some real-world perspective on this "4 years at the knee of the master" argument, consider: President William Henry Harrison, who's presidency lasted a grand total of 30 days, 12 hours and 30 minutes before he expired tragically at the age of 68.
Wikipedia:
When Harrison arrived in Washington, he focused on showing that he was still the steadfast hero of Tippecanoe. He took the oath of office on March 4, 1841, an extremely cold and wet day. Nevertheless, he faced the weather without his overcoat and delivered the longest inaugural address in American history. At 8,444 words, it took nearly two hours to read (even after his friend and fellow Whig, Daniel Webster, had edited it for length). He then rode through the streets in the inaugural parade.[51]
On March 26, Harrison became ill with a cold. The presumptive story, which has become common knowledge despite its falsity, is that the inauguration day exposure was the cause of his illness. In fact, it was more than three weeks after the inauguration before Harrison showed the first signs of ill health. The cold worsened after he was caught in a rain shower, rapidly turning to pneumonia and pleurisy.[53] According to the prevailing medical misconception of that time, microorganisms being then unknown, it was believed that his illness was directly caused by the bad weather, when, in fact, he was likely a victim of the common cold virus, exacerbated by the drastic pressures of his changed circumstances...Harrison's doctors tried cures, applying opium, castor oil, Virginia snakeweed, and even actual snakes. But the treatments only made Harrison worse, and he became delirious. He died nine days after becoming ill,[54] at 12:30 a.m., on April 4, 1841, of right lower lobe pneumonia, jaundice, and overwhelming septicemia, becoming the first American president to die in office. His last words were to his doctor, but assumed to be to John Tyler, "Sir, I wish you to understand the true principles of the government. I wish them carried out. I ask nothing more." Harrison served the shortest term of any American president: only 30 days, 12 hours and 30 minutes.[51]
Obviously, the medical sciences have advanced considerably, but death surprises most of us and comes at the least welcome of times. Even in the 21st century, 30-year-old marathoners drop dead of heart attacks, black ice sends cars off cliffs, tree limbs fall during rain storms....well, you get the point. Thats not even to mention the assassins bullet or bomb or any of the other deliberate ways in which a President might perish.President James A. Garfield lasted only 199 days before he shot by Charles Guiteau, a deranged supporter-turned-stalker.
Obviously, the odds are against any such tragedy befalling someone as protected and medically monitored as a 21st century American President, but nonetheless, isnt it a good starting premise when picking your Vice President, to not just pose the "ready to lead on day 1" question, which may seem kind of abstract, but also ask yourself:
"Would this person pass the President Harrison test? Would they be ready to lead on day 31?"