Imagine him white.

Barack Obama, that is. Amidst all the glowing talk about the possibility of his becoming America’s first black president in 2008, it’s an interesting thought experiment to imagine whether Mr. Obama would elicit this swooning buzz if he were white.

That is, let’s imagine a white guy with all of Mr. Obama’s pluses: crinkly smile, sincere concern for the little man, fine speech a couple of years ago about bringing the nation together, a certain charisma, wrote a touching autobiography. Let’s call him Barrett O’Leary.

I do not think Mr. O’Leary would be touted a year-and-change into his Senate appointment as a presidential possibility. No knock on Mr. Obama intended, mind you. For all we know, he could have the genius for national statesmanship of a Disraeli. The point is that we don’t know yet. Like any new senator, Mr. Obama has been quietly learning his way around the byzantine procedures of Senate lawmaking.

The key factor that galvanizes people around the idea of Obama for president is, quite simply, that he is black. Other things about him don’t hurt, but that’s all — they are not the deciding factor. Take away Mr. Obama’s race and he’s some relatively anonymous rookie. Barrett O’Leary, even if as cute and articulate as Mr. Obama, would have to wait at least another four years, and possibly six or seven, before being considered as a possible commander in chief.

What gives people a jolt in their gut about the idea of President Obama is the idea that it would be a ringing symbol that racism no longer rules our land. President Obama might be, for instance, a substitute for that national apology for slavery that some consider so urgent. Surely a nation with a black president would be one no longer hung up on race.

Or not. Mr. Obama is being considered as presidential timber not despite his race, but because of it. That is, for all of its good intentions, a dehumanization of Mr. Obama. We’re still hung up. What Mr. Obama has done is less important than his skin color and what it “means.” The content of our character is not exactly center stage here. We are a long way from Selma, but not yet where the Rev. King wanted us to be.

Another reason for my lack of enthusiasm for Mr. Obama as symbol is that the racial healing many might see him as portending would not happen. Among a certain kind of black person and non-black fellow travelers — roughly, those given to surmising that the levees near the Lower Ninth Ward in New Orleans were deliberately blown up — the going wisdom would be that Mr. Obama was elected only because he is merely the kind of black person whites are “comfortable” with.

With his light skin, African father and white mother, and only faint hint of what I call a “black-ccent” — the subtle vocal quality that makes most black Americans identifiable as black over the phone (yes, one can “sound black.” It’s been demonstrated repeatedly by linguistic analysis, and the “black-ccent” overlaps only partially with white Southern) — Mr. Obama would easily be cast by these types as “not too black.”

The kind of person these people see as “really black” are ones like, say, Spike Lee, who view white America warily as an alternate universe (Mr. Lee considers the levee-bombing a viable possibility, for example). Such people may be good at many things, but being an American president would not be one of them, and no such person could ever be elected to the office. If the first black president since Mr. Clinton is not Mr. Obama, it will be a black person similarly unlike Mr. Lee or Al Sharpton. As such, the crowd in question will see no significant promise in any black presidential candidate who could win. This means that Obama fans should not suppose that his election would snuff out the “AmeriKKKa” routine, which would only expire under a Conyers or Waters administration.

Yet in the grand scheme of things, I’ll take a little unintended dehumanization over naked bigotry. Perhaps it is inevitable that in the wake of a moral earthquake as abrupt as the civil rights revolution, for a while whites, in their quest to check themselves for racism — a quest I support in principle — will sometimes slip into seeing black people as lessons rather than as individuals. If the attention Mr. Obama has attracted on this basis gives him the floor to present us with an argument that he would be an effective chief steward of our country, then so be it and all power to him.

However, I remain convinced that checking ourselves for racism is also relevant to how we process our Great Black Hope. If Mr. Obama seeks the presidency, I will be evaluating him on the basis of his views and accomplishments, and the color of his skin will have nothing to do with it. This is what I read the civil rights revolution as teaching me to do, and I cannot see our more recent “diversity” fetish as a useful, or even civil, revision of such.

In other words, I will be keeping a close watch on Barrett O’Leary.

Mr. McWhorter is a senior fellow at the Manhattan Institute.