We have been told, by no less an authority than Sen. Barack Obama himself, that the recently retired Rev. Jeremiah Wright has been his pastor and spiritual adviser for the past 20 years. Wright officiated at Obama's marriage and baptized his children. There is simply no arguing about the closeness of the two men, or about the influential role Wright has played in Obama's life.

And then, in March, millions of Americans watched on television as Wright unloaded himself on the subject of the United States of America, whose president Obama aspires to be. Wright told his parishioners (who could be seen in the background applauding his remarks) that the U.S. government had engineered the AIDS epidemic to kill black people, and worked up to a peroration in which he resoundingly rejected the slogan "God bless America." No, he thundered: The right view was "God Damn America!" His parishioners roared their approval.

Needless to say, when questioned by reporters, Obama wasted no time distancing himself from those sentiments. He not only disagreed with them, he asserted, but if they had ever been uttered in his hearing at a service of his church, he would have felt obliged to leave the church. The United States has its defects, but its virtues far outweigh those defects.

Obama's repudiation of Wright's statements was absolutely essential if he intends to be a serious candidate for president. And speaking for myself, I do not for a moment doubt that the repudiation was perfectly sincere. Obama has a great many views I disagree with (probably including some I am not even aware of), but I do not doubt that he has a thoroughly balanced, sophisticated and sympathetic general view of the United States, in which hallucinations like Wright's have no place at all.

But the American people can be forgiven for suspecting that there is more here than Obama is letting on. Wright's comments on the United States weren't unleashed in the course of a drunken party or a fiery debate. They were part and parcel of a serious statement -- probably in the course of a sermon -- addressed to the members of his church, and were received by them, enthusiastically, as such. If Obama didn't hear them, it simply beggars belief that Obama could have associated with Wright so closely over a period of 20 years without being present, again and again, when Wright worked himself up to comparable frenzies and let fly to comparable effect. And while I have no doubt (to repeat myself) that the senator disagreed with such statements, it is inevitable that he sat there and tolerated them, and did not walk out, let alone dissociate himself from the pastor or church in which they were uttered.

I suspect that many whites are unaware of the social dynamics of certain black churches. Their members are devout Christians, but they suffer the inevitable routine indignities of being black citizens of an overwhelmingly white republic, and their churches are among the few places where the resulting frustrations can be expressed collectively and relatively safely. Every now and then, some black pastor (and some far more than others) will give voice to a bellow of pain that serves as a useful catharsis for such sentiments.

That is what I think happened -- perhaps quite frequently, over the 20 years in which Obama listened to Wright's sermons. And Obama, who became a public figure of note only in recent years, sat quietly through these fulminations rather than tackling his pastor about them head-on. If he had done otherwise, he would swiftly have forfeited whatever leadership role he hoped to play among his fellow blacks.

That, I think, is the only reasonable explanation of the rather muddled situation in which Obama now finds himself. It doesn't cast him in a particularly courageous light. But if he was guilty of moral cowardice, whether that fact disqualifies him for the presidency is a question every voter will have to answer for himself or herself.