Charles Murray proposes a remedy to what he calls growing cultural inequality between classes:

When it comes to marriage and the work ethic, the new upper class must start preaching what it practices.

Changing life in the SuperZIPs requires that members of the new upper class rethink their priorities. Here are some propositions that might guide them: Life sequestered from anybody not like yourself tends to be self-limiting. Places to live in which the people around you have no problems that need cooperative solutions tend to be sterile. America outside the enclaves of the new upper class is still a wonderful place, filled with smart, interesting, entertaining people. If you’re not part of that America, you’ve stripped yourself of much of what makes being American special.

So Murray’s solution appears to be telling members of the “new upper class” to change quite a few of the cultural habits that he has just described as part of what distinguishes them from everyone else. If he explained why they should or would do this, I must have missed it. Murray seems to hint at it briefly towards the beginning, and he appears to be interested in reviving the “common civic culture” whose unraveling he details, but he never makes an argument for why the “new upper class” should follow his advice. It’s implied that declining rates of marriage, religious practice, and “industriousness” among the “new lower class” are the real problems that need to be fixed, but the remedy appears to be little more than encouraging the “core of civic virtue” in “Fishtown” by validating “the values and standards they continue to uphold.” That may be encouraging for the people whose habits are being validated, but it doesn’t tell us why the people currently not practicing those habits are going to have much incentive or reason to start.

If I have understood Murray’s argument, the cultural separation between classes became self-reinforcing decades ago, and increasing separation and isolation will keep happening “no matter what.” As he writes elsewhere in the op-ed:

The economic value of brains in the marketplace will continue to increase no matter what, and the most successful of each generation will tend to marry each other no matter what. As a result, the most successful Americans will continue to trend toward consolidation and isolation as a class.

The separation that Murray has identified will keep happening and can’t really be slowed, much less reversed, by any policy mechanism, but he thinks that the SuperZIP-dwellers can partly remedy this by rejecting isolation:

Everyone in the new upper class has the monetary resources to make a wide variety of decisions that determine whether they engage themselves and their children in the rest of America or whether they isolate themselves from it. The only question is which they prefer to do.

The trouble here is that Murray has just thoroughly detailed which choice they prefer, and he hasn’t given them much of a reason to choose differently, except to say that the places they live are “sterile,” their way of life is “self-limiting,” and they are “stripping” themselves of much of what makes “being an American special.” What is missing throughout the op-ed is any appeal to republican or democratic principles, civic duty, national unity, or social solidarity. Perhaps he thinks the reasons to do as he advises are obvious and don’t require explanation, but it is a curious omission. Murray clearly believes that the “new upper class” ought to engage “in the rest of America” to reduce cultural inequality, and he wants it to be strictly voluntary, but he gives no clear reason why anyone should volunteer.

P.S. Even though Murray has described the “great divide” in America in terms of culturally separated classes rather than in terms of increased economic inequality, it is likely that someone like Romney doesn’t see this divide and might not find much wrong with it if he did.