Bill Cosby didn’t invent the politics of respectability — the belief that good behavior and stern chiding will cure black ills and uplift black people and convince white people that we’re human and worthy of respect. But he certainly gave it a vernacular swagger that has since been polished by Barack Obama. The president has lectured black folk about our moral shortcomings before cheering audiences at college commencements and civil rights conventions. And yet his themes are shopworn and mix the innocuous and the insidious: pull your pants up, stop making racial excuses for failure, stop complaining about racism, turn off the television and the video games and study, don’t feed your kids fried chicken for breakfast, be a good father.

As big a fan as he is of respectability politics, Mr. Obama is the most eloquent reminder that they don’t work, that no matter how smart, sophisticated or upstanding one is, and no matter how much chastising black people pleases white ears, the suspicions about black identity persist. Despite his accomplishments and charisma, he is for millions the unalterable “other” of national life, the opposite of what they mean when they think of America.

Barack Obama, like Michael Brown, is changed before our eyes into a monstrous thing that lacks humanity: a monkey, a cipher, a black hole that kills light. One might expect the ultimate target of this black otherness to have sympathy for its lesser targets, who also have lesser standing and lesser protection, like the people in Ferguson, in Ohio, in New York, in Florida, and all around the country, who can’t keep their unarmed children from being cut down in the street by callous cops who leave their bodies to stiffen into rigor mortis in the presence of horrified onlookers.

President Obama’s clinical approach to race was cemented after the 2009 Henry Louis Gates Jr. incident — in which the Harvard professor and the white police officer who arrested him for breaking into his own house were invited to the White House to commune over a beer — convinced him that he should talk race only when his hand was forced.

He has employed a twin strategy: the “heroic explicit,” in which he deliberately and clearly assails black moral failure and poor cultural habits, and the “noble implicit,” in which he avoids linking whites to social distress or pathology and speaks in the broadest terms possible, in grammar both tentative and tortured, about the problems we all confront. It’s an effort that hinges on false equivalencies between black and white and the mistaken identification of effect for cause.

MR. OBAMA spoke twice in the aftermath of the Ferguson grand jury’s decision. He spoke Monday night about America as a nation of laws and said that we must respect the jury’s conclusion, even if we don’t agree with it, and make progress by working together — not by throwing bottles, smashing car windows or using anger as an excuse to vandalize property or hurt anyone.

On Tuesday, the president doubled down on his indictment of “criminal acts” and declared, “I do not have any sympathy” for those who destroy “your own communities.” While he avoided saying so, it was clear that his remarks were directed at the black people who looted and rioted in Ferguson. But their criminal activity is the effect of going unrecognized by the state for decades, a crime in itself. As for the plague of white cops who kill unarmed black youth, the facts of which are tediously and sickeningly repetitive and impose a psychological tariff on black minds, the president was vague, halting and sincerely noncommittal.