Allow me to preface what I am about to say here with, I have always had a tremendous amount of respect for Gen. Powell. In fact, I could spend an entire post detailing my reasoning, but I can sum it all up in much shorter fashion:
I have said many times before, the best people for the job of President, do not want the job. This certainly is the case here.
Gen. Powell is an intellectual, a diplomat, a soldier, and most of all, a leader. But for numerous reasons (one of which is his wife's health), he has no desire whatsoever, to be President. I would say the prime reason for this is, the intense scrutiny and pressure that comes with the territory is so overwhelming and so frustrating that it is just not healthy for anyone. By reading this WaPo article you can get a mere taste of the world that people at this level, must endure day to day, week to week. The arm twisting, the manipulations (and so forth) are so intense and so relentless, a person could easily feel pulled in several directions, simultaneously.
With his military retirement pay, generous book royalties and speaking fees, he makes a decent living. He doesn't need the money. He has been at the top of the mountain in the military, so he doesn't desire the power. He understands the concept, with much power comes much responsibility. For him, power is not a toy. With this in mind, can we blame him for not wanting to subject himself and his family to this form of self-flagellation?
You see, the people that want to be President are usually narcissists. They are not the reluctant heroes. They are the ones that cry, "Pick me pick me, I want to do it! I can do it, I am the best. Pick me, pick me." They want the world to revolve around them, they want to be the center of attention. And if they can't be the main attraction, they either blow up (See:Bill Clinton) or take their ball and go home (See: Ross Perot).
Clinical psychologist Robert Godwin (AKA Gagdad Bob from One Cosmos) has a more in-depth examination into the mind of a narcissist. I recommend reading the entire article, but let's look at a particularly noteworthy passage that is pertinent to this argument.
After characterizing some traits of a narcissist, he inserts this little aside (emphasis is mine):
...this is why it is generally a mistake to elect someone president who desperately wishes to be president, such as LBJ, Nixon, Al Gore, Clinton. Our better presidents could take it or leave it, because they already had satisfying lives and were capable of generating meaning from within....
General Powell has already proven himself, what else would he need to prove? He needs no introduction anywhere. His face is pretty universally recognized and his name is a "household name" that most reasonably intelligent people already know. Whether it be written or spoken, people know who he is. And, if there is one person in the world that we could say is actually self-actualized, it would be Gen. Powell.
Can we say the same thing about the bulk of today's leaders that have been entrusted to lead this nation? I highly doubt it.