The elites create problems for their middle class by putting them continually at war with—and taking all the casualties inflicted by—an imported underclass.
This war is good for the elites in several ways. In fact, there's almost no downside for them, other than the rare case in which one of them gets assaulted or killed by a member of the underclass (I'm thinking here of Bill Cosby's son, or of the case of Jonathan Levin, son of Time Warner chairman Gerald Levin).
They apparently have decided that they can risk those rare losses in return for the benefits.