Exactly this, with those dangerous Maga Extremists that "Threaten Democracy"Once a targeted group has been vilified within a population, it is very difficult for them to organize an action against the actual aggressors.
The portion of the populace that has not accepted the targeted group as monsters, are still hesitant to align with or render aid to the targeted.
The aggressors were in control broadcast and private communications. It made it difficult to send a message of warning. The aggressors could control the narrative and undermine any counter-opinion and/or observation.
Edit to add: The ghettos did form a resistance, but it was short lived.