What is the most important factor for genocide to happen and why?

What is the most important factor for genocide to happen and why?

Is it referring to the others as "vermin," "rats," or people not worthy of the same rights and protections as the majority, or is it not wanting to cross authority and suffer the consequences or wanting to just go along with everyone else?

Dehumanizing the targeted group
Blind obedience to authority
Both
Other, I'll explain below
Select gender and age to cast your vote:
What is the most important factor for genocide to happen and why?
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