But those people can only exist in co-existence with the larger class of people surrounding them and executing the "rule" of the country.

As the population is culled the need for administrators dwindles. Therfore the population of administrators also must be proportionally reduced. There is no reason to think the administrators would be spared the propaganda or the subversion. It would only introduce the completely unnecessary threat that one of them would grow a conscience and expose the subversion.