Is what
communists (although it has happened in other countries, including the
U.S. to a limited extent) give people who do not follow the
party line. It mainly involves a constant barrage of
propaganda - but has also been known to include
forced labor,
torture and
drugs - in order to cause
brainwashing.
A good visual, although not necessarily realistic, depiction of reeducation can be found in Stanley Kubric's film "A Clock Work Orange."