In other words, they've behaved like ordinary people behave, as in badly.
This was first made possible in America broadly by the Kennedy and then the Reagan tax cuts (Irish anyone?), which took away the high-taxation-goad that prodded income into productive investments which in turn benefited more people, but this never occurs to the author, here:
[A]round the world and throughout history, the wealthy have advanced the crystallization process in a straightforward way. They have taken their money out of productive activities and put it into walls.
The whole point of conservatism has been that human nature is mixed, so that "class" is mostly irrelevant. The author, however, is preoccupied with it, especially the "New American Aristocracy", which means he's a liberal who is (mostly) convinced some people are more equal than others for various reasons, which he goes to great, and sometimes convincing, lengths to demonstrate, and criticize.
That's a start.
Conservatives answer that good people and bad people populate the whole at every level, and that everyone has a little bit of each in them at the same time. Conservatives also believe that good government is government which encourages the good in everyone and discourages the evil. Bad government denies that this is government's responsibility at all, or it denies that one of these two irreducible facts of life is a fact so that you get liberal government which lets people run amok or tyrannical government which is too restrictive.
The author's answer is more equality when understanding how we all already are equally good and evil would be better. It's the peculiar blind spot of liberalism, the analogue of which in conservatism is failing to see the good in people:
But we do have a blind spot, and it is located right in the center of the mirror: We seem to be the last to notice just how rapidly we’ve morphed, or what we’ve morphed into. The meritocratic class has mastered the old trick of consolidating wealth and passing privilege along at the expense of other people’s children.
