The United States Presidency is not a celebrity position. Real, hard decisions will need to be made in which human lives will be lost. What the president chooses will either increase or decrease human suffering, and I, for one, would like someone who has already learned the consequences of their decisions firsthand before attaining the most powerful position on this planet.
Here is McCain's most effective ad to date. Via Hot Air.
You know, I am a believer in … in knowing what you’re doing when you apply for a job. Uh, and I think that … if I were seriously to consider running on a national ticket, I would essentially have to start now, before having served a day in the Senate. Now there may be some people who are comfortable doing that, but I am not one of those people. — Barack Obama, 2004