The principal difference, however, is a big one: Powell, at the time he considered running, had been chairman of the Joint Chiefs of Staff -- or, as he put it, "the No. 1 person in the armed forces of the most powerful nation on earth." He had directed one of the most stunningly successful wars in history, when we evicted the Iraqi army from Kuwait.
Obama's achievements, on the other hand, are mostly in his future. With eight years in the Illinois legislature and two years in the U.S. Senate, he's not a political novice. Having been a faculty member of the University of Chicago Law School, where debate is a contact sport, he's not untutored in weighty issues. But far more than Powell -- or any of his potential rivals for the presidency -- he is an unknown quantity.
The way in which he resembles George W. Bush -- his thin resume -- is not one that will help him. It may be cancelled out, though, by the ways in which he conspicuously contrasts with the outgoing president -- notably, being thoughtful, articulate and seemingly open to opposing views. Bush is the commander in chief. But it's Obama who gives the effortless impression of command.
His immediate challenge is to simultaneously assure Democratic partisans that he is liberal enough for them while convincing everyone else he is conservative enough for them. Being opposed to the Iraq war from the outset will give him latitude to depart from party orthodoxy on other issues, if he has the vision and nerve -- make that audacity -- to do so.
In the end, Obama could be another John Kerry, whose military biography was not quite enough to counter his merciless depiction as another out-of-touch liberal. Or he could be another Ronald Reagan, who had to overcome demonization on his way to proving that Americans will take a chance on a philosophy they don't entirely share, if it comes with the right leader.