Is America ready for a black president? That's like asking if country music is ready for Carrie Underwood. If you make it on "American Idol," you've got it made in America, and if you can have not one but two different black presidents on "24," ditto. Most citizens would probably breathe a sigh of relief if they woke up tomorrow to find that David Palmer, assassinated last season, had been resurrected and installed in the real Oval Office.

As it happens, art is following public inclinations rather than leading them. The truth is, America was ready for an African-American president more than a decade ago, when Colin Powell was raising pulse rates across the political spectrum. A poll in the fall of 1995 had him beating President Clinton by a margin of 51 percent to 41 percent. When he decided not to run, it wasn't because experts didn't think he could win.

Barack Obama is the Colin Powell of 2008 -- a charismatic leader with a quintessentially American backstory and an appeal that transcends traditional divisions. That a Hawaiian-born son of a Kenyan father and a white mother, who grew up in Indonesia and has a name on loan from al Qaeda, could generate such broad excitement proves something Powell already demonstrated: Americans can surprise you.

It is a cliche to note that many of our most beloved celebrities -- Michael Jordan, Oprah Winfrey and Tiger Woods -- are black. But cliches sometimes develop only because they tell important truths: In this case, that white (and Hispanic and Asian) Americans have no trouble revering and identifying with successful members of a group that most whites once regarded as fundamentally alien, not to mention inferior.

The resemblance between Obama and Powell is unmistakable. Both rose in the world without the racially conscious approach of many African-American leaders, and without any particular debt to black interest groups. Both excelled in white-dominated institutions -- Powell in the U.S. Army, Obama at Harvard Law School, where he was the first African-American president of the Harvard Law Review.

Both have the knack of appealing to whites without evoking the slightest twinge of guilt. In fact, both do just the opposite, by demonstrating the enduring reality of the American dream -- that here, someone with talent and drive can overcome obstacles that in other societies would be impassable. Both possess a quality of relaxed gravity and wisdom that is rare among political aspirants, even as they embody the can-do optimism Americans prize in their leaders.

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.