Why was nonviolent action so effective, and what unique leverage does nonviolent resistance have in the face of power and force ?

The correct answer to this open question is the following.

Nonviolent action was so effective because, through pacific demonstrations, African Americans demonstrated the injustices that lived and endured due to white people's decisions and actions. The unique leverage that nonviolent resistance had in the face of power and force was that with their pacific and non-violent resistance, they showed the people of the United States that they were demanding what was fair and right in an orderly way. It also showed the brutality and aggression of the police and white people. American citizens in all the US territory started to show sympathy for the African American motives.

increasing defense spending.

explanation:

they wanted the u.s. to fight on the side of the central powers.