Why do many ignorants in the USA consider southern Europeans "less White" than northern Europeans?

Race is Race and all peoples that are native to Europe are racially White.Whites with blond hair and blue eyes are not the only Whites in planet earth! hence Whites also have black,brown,red hair and brown,green,hazel eyes! look at At Adolf Hitler he physically possessed dark hair and eyes yet he is STILL racially White!!!!!!!!!!!!!