The red scare was a period where the ideas of anti-communism were very strong in the United States of America that was marked by a growing anti-immigration nativism movement that, according to many, were founded out of fear of the unknown or pure prejudice.
That sort of situation created the grounds for the arise of the Ku Klux Klan, a white supremacist protestant group of distorted values.
So the answer is Nativists and the Ku Klux Klan.
