The pundits are fond of saying that the vice presidential candidates don't make much difference in presidential elections, but this time could be different.
To put it crassly, the odds of a president dying in office are getting shorter and shorter.
For almost 150 years, we had presidents dying every 20 years: Harrison in 1841, Taylor in 1850, Lincoln in 1865, Garfield in 1886, McKinley in 1901, Harding in 1923, Roosevelt in 1945 and Kennedy in 1963.
But it's been 45 years since the last time. And this year both presidential candidates are at risk: Obama because of the ever-present threat of assassination, and McCain because of his age. At 72, he would be the oldest president ever elected; and because of the torture he suffered during the Vietnam war he's probably older, medically speaking, than his chronological age.
So it behooves the electorate to take a closer look than usual at the vice presidential candidates this time because one of them very well could end up in the White House.
On one hand, you have Joe Biden, chairman of the Senate Foreign Affairs Committee and former chairman of the Judiciary Committee, which gives him great expertise in two of our most urgent problems: America's isolation in the world community and the politicization of the justice system. Whatever you think of him, he clearly has the gravitas to step into the top spot if, God forbid, it becomes necessary.
And Sarah Palin? Someone who has been in office for only two years? With zero experience in national or foreign affairs? Does anyone really think she'd be ready for that 3 a.m. phone call?
It's clearly a cynical attempt to appeal to disgruntled Hillary voters. But I think even Republican women will be offended by McCain's implicit assumption that any female candidate, no matter how lightweight, will do.