Let me preface this by saying I am chareidi, ashkenazi, and live in israel. We have friends who are sephardi of all types and nationalities. My kids go to school with many lovely sephardi children from beautiful sefardi families.
However, there is a type of person who can be ashkenazi or sephardi, that exhibits a type of negative behavior which is referred to as being ‘sefardi’ (or worse). That type of behavior is not limited to sephardim. Americans will have a hard time understanding this if they haven’t experienced it themselves.