Since no Moorish style expulsion is going to happen, the best we might actually be able to swing is private cities that will be protected by walls/fencing and have entrance criteria. Imagine the pure joy of living in a place where psychiatrists have screened out the psychopaths, sociopaths, the mentally ill, the impulsive, the hot tempered, the depressive, the people who don't speak English, and the non-American citizens as a starting point.