The more extreme forms of political ideology can and do inspire a level of fanaticism which rivals the worst of the religious forms. (Numerous examples of this were observed in Malaysia’s 12 year battle against the communists, during what was known as the “Malayan Emergency”).
Not surprisingly perhaps, traces of this same “all or nothing” mentality are often observable even after a person abandons a cult. Speaking for myself, it took some time for the realisation to sink in that things are seldom ever clearly black and white. Instead, you are much more likely to be dealing with various shades of grey. This is particularly the case with politics - where a healthy dose of cynicism is a bloody good place to start from!