In Kohlberg's empirical studies of individuals throughout their life Kohlberg observed that some had apparently undergone moral stage regression. This could be resolved either by allowing for moral regression or by extending the theory. Kohlberg chose the latter, postulating the existence of sub-stages in which the emerging stage has not yet been fully integrated into the personality.  In particular Kohlberg noted a stage 4½ or 4+, a transition from stage four to stage five, that shared characteristics of both.  In this stage the individual is disaffected with the arbitrary nature of law and order reasoning; culpability is frequently turned from being defined by society to viewing society itself as culpable. This stage is often mistaken for the moral relativism of stage two, as the individual views those interests of society that conflict with their own as being relatively and morally wrong.  Kohlberg noted that this was often observed in students entering college.  
An important consequence of giving highest priority to the metaphor of Moral Strength is that it rules out any explanations in terms of social forces or social class. If it is always possible to muster the discipline to just say no to drugs or sex and to support yourself in this land of opportunity, then failure to do so is laziness and social class and social forces cannot explain your poverty or your drug habit or your illegitimate children. And if you lack such disciple, then by the metaphor of Moral Strength, you are immoral and deserve any punishment you get.