I'll tell you why Barack Obama said what he did.

When he was asked last week about the racially-charged arrest of Harvard Professor Henry Louis Gates, the president could have — and as a political matter, should have — given a diplomatic non-answer. Instead, he gave a forthright response he later had to apologize for: police in Cambridge, Mass., he said, acted "stupidly'" in arresting Gates, a prominent black scholar, at his own home, committing no crime.

So why did Obama, usually the smartest cookie in the jar, not do the politically-intelligent thing?

There, but for . . .

I think it's simple. I think he looked at Henry Louis Gates and saw his brother-in-law, his nephew, maybe himself if he were not who he is.

I think he did what black men habitually do when news breaks of some brother beat down, gunned down or simply thrown down and handcuffed for no good reason: he breathed, "There, but for the grace of God . . ."

Of course, Americans of many cultural stripes have put themselves in Gates' shoes in recent days. And many have found him wanting. They say he caused his own plight by being — to what degree is a matter of dispute — uncooperative with a police officer. They fault him for crying racism when it's just as likely, they say, his arrest, misguided as it was, had nothing to do with race.

The first argument misses the point. Certainly few people would dispute that Gates failed Black 101 and, for that matter, Common Sense 101 in being uncooperative to whatever degree. But it's equally obvious to some of us that a white man, whose only "crime" was complaining, would likely have enjoyed more leeway than Gates did.

The second argument is naive. One white guy I know recounts his own experience — cop barged into his home at 3 a.m., rousting him from bed, demanding I.D. — and says: "this [expletive] happens all over the place and it has nothing to do with race.'"

Personal experience

And I say:

I'll see your 3 a.m. roust and raise you Tony, jacked up on a street in Harlem, Bill, with a cop's gun to his head, Bryan, pulled over for an air freshener on his rear view mirror, James, ordered to pull down his pants and lie on the curb, Robert, threatened with injury for drinking beer in the parking lot with friends after work. And that's just among guys I know, including three preachers.

Now, broaden it to include the bridegroom shot to death on his wedding day, the African immigrant killed while reaching for his wallet, the Maryland man beaten senseless as he lay in bed, the Miami man beaten to death for speeding, the dozens of men jailed on manufactured evidence in Los Angeles and manufactured police testimony in Tulia, Texas, the man sodomized with a broomstick in New York. Are we supposed to believe it coincidence that the men this happens to always happen to be black?

Some of us do. Some of us have the luxury of never connecting the dots, seeing instead one discrete incident over here and tsk tsk, how terrible that is, and another discrete incident over there and tsk tsk again. And then move on and leave it behind.

But others don't have that luxury, don't get to move on and leave it behind. Others carry it like luggage, wear the residue like sweat, into every encounter with every cop, both good and bad: not always memories of what did happen, but fear of what could.

Unnecessary fear? Sometimes; there are many great cops out there. Perfectly valid fear? All too often.

Here, then, is the take-away of the Gates affair: apparently every black man knows what that fear is like, be he professor, preacher, pundit.

Or president.