Or at least a one in five possibility of he or she being president, based on historical precedent.
Sarah Palin often defends her adequacy for the position of V.P, even pointing out that her inability to name a single Supreme Court decision she disagreed with, other than Roe v. Wade, didn't matter since even as Vice President she will not be in a position to change the "law of the land."
In effect, Biden and Palin are running for two distinct and conceptually different positions. The first, with the title on the ballot is that of Vice President, a position with actual independent authority that is less than a cabinet secretary or committee chair in Congress. As a trusted adviser to the President the position can be as powerful as Cheney or Gore were, or as minimal as Barkley or Agnew.
The other position is that of President of the United States. And by electing her Vice President, there will be no confirmation of her elevation to the Presidency. It will be done on the spot at the time of death; and now also in the event of disability of the President since passage of the 25th Amendment.
This anomaly of a person running for both a minor government position along with the potential of, with no further confirmation, having the most powerful position in government can only be understood by looking at the history of this position.
Our constitution was predicated on there never being any political parties, "factions" they were called then, which were strongly warned against in the Federalist Papers. So, if we were to have one unified group of respected representatives, it made sense that both would share common values, and the one who came in second should be the one to inherit the job if events required.
It is how it might be in your Rotary Club or P.T.A. So for the first two elections no one ran for Vice President. The second place candidate who became the Vice President must have possessed the qualities also to be President, since that was the office he was running for. The man who ran under those rules could never say that it is not that important a position, since only until the electoral votes were counted did he know whether he would actually be the president.
With the development of parties, this conceptual framework no longer worked, and with the 12th Amendment of 1803 we voted for a President, and what had become something unexpected both politically and structurally, Vice President. So, the position became more of a political decision, balancing regions and groups, than selecting the most qualified person, as it had been originally conceived of.
Senator Biden must run against Sarah Palin for the second component of this job, that of President, and not for the position and duties of Vice President. As such he has an obligation that transcends the regular norms of courtesy. While he and Obama have subjected themselves to scores of debates and hundreds of interviews, Palin is asking to be the one who decides on issues affecting the lives of the three hundred million people in our democracy, based on only this single debate.
This is an historical anomaly, a defect in our system of choosing a President, that has brought us this close to having a President who is almost universally considered unfit for the job. It is not only the right, but the obligation, of Senator Biden to perform the public service of pointing this out.