In fact, it is a pretty good parody of the "Galt's Gulch" ideal as expressed by today's admirers of the works of Ayn Rand. Remember that in the story, the Valley began only as a vacation spot. When quitting became illegal, the capitalists needed a hideout. As things got even worse, the Valley became a refuge. One thread not followed was that the capitalists in the Valley were a diverse lot who disagreed on much, not the least of which was Ragnar's piracy. The greatest composer of the age was the happy neighbor of a man who was tone deaf. They only agreed on the non-initiation of force. This has been transmogrified into a desire to live among people who agree with you on matters of art, architecture, and music, as well as politics and economics, to say nothing of the Copenhagen interpretation of quantum mechanics.
(By a happy error, Luke's link on the Electoral College actually took us to an article about Constantinople, here: http://www.delanceyplace.com/view-archives.php?p=3212. In a culture defined by religion, the city held large religious minorities. Constantinople thrived as a center of trade and commerce. However (and more to the point), the scientific revolution of the Age of Reason came not from any one place, but from diversity across a wide geography, eventually spreading beyond Europe to America. An isolated society of London Newtonians would only have imploded, as in fact, physics nearly did in England, when they cast themselves intellectually free from the Continent.)
I posit a theorem of sociology that no successful society is monolithic.
That leaves unaswered the basic problem set of how to (1) create (2) protect and (3) nurture an open and diverse society? I have some observations and conclusions, but no easy answer. I do assert that walling yourself in is not the way to do it.