Why were the KKK so powerful?

Answer 1

because no one tried to stop them... until later

(To back up your answer):The North did try they were just overpowered.

Answer 2

The Ku Klux Klan was powerful because they instilled fear through acts of violence and intimidation, targeting African Americans and other marginalized groups. They also had support from certain government officials and law enforcement, allowing them to operate with impunity in some areas. Additionally, they leveraged Propaganda and mass gatherings to recruit members and spread their message of white supremacy.