Weird shit of so much of this racial talk is so many of these people would just be considered "Roman" back in the day. 2,000 years ago a Sicilian was racially just an average member of Western Civilization. This multi racial-cultural that everyone fetishes is not gonna happen. The definition of white will expand just as it was expanded for Italians.
Mainland Italians are a mix of Italo-Roman, Greek, Norman and Germanic (mostly in the north).
The island of Sicily was occupied by Arabs for centuries and is still today quite culturally distinct from mainland Italy.
For many Americans, due to the amount of immigrants from the island, Sicilians are probably their idea of what 'Italians' look like.