Manicism, in one of its possible forms, distinguishes reality between two contrasting principles: good and evil. 
Ideological Mannequeism leads to the analysis of people, social groups, parties, nations, religions, and other realities in a strongly dichotomous way.
In that perspective, humans are labeled good or bad as they become part of one side or the other. 

In the twentieth century there were two infamous examples of ideological Mapoliticism: Leninism Marxism applied in the USSR and elsewhere, and Hitler's National Socialism. 
Recent examples could be given that show how this phenomenon still has a long life in different areas of our society.

Let's give two examples: many systematically condemn the actions of "white" Westerners and remain in silence in the face of actions by isolated Indians if they kill any foreigners who step on their territories. 
A second example leads some to believe that any proposal for economic reforms in the liberal sense automatically goes against workers' rights, while any reform that gives the state more weight in the economy is presented as socially positive.

The reality is much richer and more complex. The Manic analyses simplifies, distorts and denies data adverse to one's own ideology, and over-emphasize favorable data. 
But beyond deceptive Mathechians and ideologies that condemn adversaries in mass, the love of truth and justice leads to the recognition that in many human groups good and evil are mixed, right and wrong, the noble and the perverse.

It is not a question of denying the presence in the world of positives and negatives. What matters is to give each one what is right for them, without ideological reductionisms and without Manichianisms oriented to summary sentences against some human beings, when in reality, in most cases, along with forgivable errors and defects, there are also good elements that deserve to be recognized.