Chinese Americans faced the brutality of the Irish, who were the main competition for jobs. Labor Unions also disliked the immigrants, who were used as 'strike breakers' because of their need for jobs. After the Chinese Exclusion Act, the Chinese still created there own new element of American Society--Chinatown.
I don’t know for sure but I would assume it’s the Holocaust that Hitler introduced as a way of removing and Jews from Germany living the country with citizens who were pure arien.