Critics of Djilas (mostly Trotskyists and orthodox Marxists) argued that his thesis was a "pamphlet of betrayal"—a disgruntled ex-communist justifying his split. They claimed that the bureaucracy was a "degenerated workers state" that could be reformed, not a permanent new class.
"The revolution is over. The new order means... the creation of a new class. The struggle for the revolution is replaced by a struggle for rank and position." Milovan Djilas Nova Klasa.pdf
After World War II, Djilas rose to the pinnacle of power as Vice President of Yugoslavia. He was the heir apparent to Tito. Yet, unlike the sclerotic bureaucrats of the Eastern Bloc, Djilas began asking dangerous questions. He traveled to the Soviet Union and saw the privileged lives of the nomenklatura . He returned to Yugoslavia and looked at his own party officials. Critics of Djilas (mostly Trotskyists and orthodox Marxists)