Thomas Sowell explains in a column this week why the federal government’s goal of making communities more “inclusive” is doomed to fare as poorly as other government programs that meddle with private decisions about housing.

Individuals and groups of all sorts have always differed from one another in many ways, throughout centuries of history and in countries around the world. Left to themselves, people tend to sort themselves out into communities of like-minded neighbors.

This has been so obvious that only the intelligentsia could misconstrue it — and only ideologues could devote themselves to crusading against people’s efforts to live and associate with other people who share their values and habits.

Quite aside from the question of whose values and habits may be better is the question of the effects of people living cheek by jowl with other people who put very different values on noise, politeness, education and other things that make for good or bad relations between neighbors. People with children to protect are especially concerned about who lives next door or down the street.

But such mundane matters often get brushed aside by ideological crusaders out to change the world to fit their own vision. When the world fails to conform to their vision, then it seems obvious to the ideologues that it is the world that is wrong, not that their vision is uninformed or unrealistic.

One of the political consequences of such attitudes is the current crusade of Attorney General Eric Holder to force various communities to become more “inclusive” in terms of which races and classes of people they contain.

Undaunted by a long history of disasters when third parties try to mix and match people, or prescribe what kind of housing is best, they act as if this time it has to work.

It doesn’t matter how many government housing projects that began with lofty rhetoric and heady visions have ended with these expensive projects being demolished with explosives, in the wake of social catastrophes that made these places unlivable.

To those with the crusading mentality, failure only means that they should try, try again — at other people’s expense, including not only the taxpayers but also those who lives have been disrupted, or even made miserable and dangerous, by previous bright ideas of third parties who pay no price for being wrong.