You’d think it would be a simple question: How popular is Barack Obama?

And you’d think it would have a simple answer: According to a recent Gallup poll, the president’s approval rating stands at 49 percent, the first time it’s slipped to less than half. Of course, Obama — you may have heard this somewhere — is our first African-American president and it is a reliable truism that when race enters the picture, “simple” leaves it.

Hence, when you parse the Gallup numbers more closely, you discover a not-so-startling divide. It turns out that among non-white voters (meaning in this case, African-Americans and Hispanics), Obama’s approval rating remains stratospheric. A staggering 91 percent of blacks and a healthy 70 percent of Hispanics approve of the job he’s doing.

Among non-Hispanic whites, on the other hand, Obama is cratering. Just 39 percent give the president a passing grade.

Richard Prince, a black journalist who writes an online column for journalists, headlined a piece on the poll findings as follows: “White Defections Drag Down Obama Rating.” Which is a fair reading, I suppose. But you could just as fairly headline it: “Non-white Support Inflates Obama Rating.”

We are not just arguing tomato to-mah-to here. No, the point is that the headline Prince didn’t use, like the dueling approval ratings themselves, testifies that race retains its power to shape — and misshape — perception.

Granted, that will be an obvious, even shopworn, observation to anyone with the slightest experience in this all-American conundrum. But it assumes added urgency when you consider that this perceptual gap isn’t measuring the impact of race on how we view this year’s trial of the century, but, rather, an actual president of the United States and, by extension, the state of the Union.

So one wishes, for our own sake, we could learn to see past our well-worn racial narratives. But racial narratives aren’t so easily put aside.

Not that this is the first time polling has quantified a racial divide. Far from it. This one, however, seems especially stark and consequential.

Again, we’re talking about a president — and there is a lot of space between 39 percent and 91 percent. But then, Obama has long been the unwitting catalyst for a raucous national discussion on the meaning and impact of race. Because he exists — and really, where race is concerned, he’s done little more than that — we find this discussion overtaking us everywhere from our newspapers to our televisions to our barber chairs.

Who could blame him if sometimes Obama himself feels like shouting that he’s not the black president. He’s the president. For all the good that would do.

The man made history and that history comes with a burden. More even than most presidents, he becomes a symbol, a lightning rod, a focal point — not simply for arguments over the economy, the wars and health care, but for all our tangled, contradictory and unresolved confusions and aspirations of race.

This is what we see quantified in that Gallup Poll. The difference in perception it documents serves as a reminder that for two people to see a thing in the same way, it helps to be standing in the same place looking in the same direction. And we black, white and brown Americans are not there yet.

From where I sit, Obama’s performance has been neither as execrable as the rating among whites would suggest, nor as walk-on-water miraculous as the rating among blacks and browns would have us believe. And that gap between them is less a measurement of a president’s performance than of a nation’s enduring irresolution.

The poll was meant to be a window. It became a mirror instead.