Wednesday will be Hurricane Katrina’s one-year anniversary, and assorted wise folks will be trotted out to intone that Katrina revealed black poverty as “America’s dirty little secret.”

Some secret, though, when the exact same people rue that white people supposedly think all black people are poor, and bristle to see “poverty given a black face” when news articles focus on black welfare mothers.

So the “secret” bit is, we can assume, a pragmatic routine. These people want to turn our heads towards how “the persistence of racism” made all of those faces in the Superdome — and by extension, among poor Americans generally — black.

Now, it could well be that if racism is not completely dead, that racism is the cause of so many blacks being poor. But correlation is not cause. Of course, the “dirty little secret” crowd consider the causal relationship here beyond question. But have they really checked?

They are deeply moved, for instance, by segregation. The precious wisdom goes that when too many poor blacks live together in one place, societal breakdown is inevitable. Never mind that this idea, divorced from the big words and flabby statistics it is usually couched in, sounds alarmingly like something Bull Connor or David Duke would say about “those people.” But the question is why there are struggling but stable working-class areas like Little Village in Chicago, where three out of four people are Latino.

And as for the idea that the departure of middle class black role models did the Lower Ninth in, why didn’t this happen on the Lower East: Side, that is, in New York back in the day, when tenements teeming with poor immigrants were Shangri-la compared to today’s inner cities?

But wait — isn’t it that low-skill factory jobs moved away decades ago? Well, ask for studies comparing black poverty in cities where factory jobs stayed put with ones where they left, and notice that it has never even occurred to people taking this line to even address the issue with curiosity or logic.

Interesting, then, that in Indianapolis there was no major exodus of low-skill jobs from easy reach of poor blacks. Yet, the same inner city problems emerged there as elsewhere. Meanwhile, a recent study by community service expert John Foster-Bey showed that across several cities, the relocation of low-skill jobs has had only minor effect on employment rates among undereducated urban young men — and as often as not, more on white ones than black ones.

The reason too many black people in pre-Katrina New Orleans were stuck in menial jobs was not because white people didn’t like them. If anything, it was because 40 years ago some white people liked them too much.

In 1972 there were about twice as many people living on welfare in New Orleans as in 1960. This was because of a nationwide loosening of welfare requirements, designed to get poor blacks on the rolls, amply documented in sources from the era. White activists embraced this as giving black people a break after Jim Crow. But legions of people ended up staying on welfare, for good. A new kind of unemployment set in, inert whether the Republican Party was up or down. Add to this how the New Welfare gave men a pass on supporting their children and you got a new kind of black community.

In 1996, welfare reform put a five-year cap on dependency. In 1990, 27,774 families had been on welfare in New Orleans, but by 2002 only about 7,000 were. However, when Katrina hit, Lower Ninth Ward residents were only nine years past welfare reform. Naturally they were not living tranquil middle-class suburban lives: it takes longer than that to undo three decades of a social bureaucracy that sapped initiative and responsibility from people who deserved better.

What we saw on TV was people making the best of themselves after lives of betrayal by a system that taught them not to work for a living. This was the “dirty little secret” that Katrina revealed.

It wasn’t black people’s fault that influential whites thought it was progressive to teach poor blacks to replace “We Shall Overcome” with “Turn On, Tune In, Drop Out.” Nor is there anything “black” about fatherless boys, growing up in neighborhoods where working 9 to 5 was optional, being so likely to turn to crime, many of them now returning to terrorizing New Orleans after racking up the homicide rates in Houston since last August. Anyone who saw Katrina’s black victims as undeserving laggards 1) had a dim interest in facts and 2) was numb to suffering.

However, the exact same charge applies to those who saw Katrina as a “wake up call” about “institutional racism.”

To ignore the unintended mistakes of the Great Society neglects history. To teach people that nothing will improve their lives short of a utopian society with a completely level playing field that no one expects to ever exist is to dismiss them.

Sadly, that is exactly what we are going to watch one “thoughtful” commentator after another doing all next week.

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