No If they were just normal white Americans, they would simply be Americans. Like the British and German descended Americans. American culture at it's core is an British descended one and then a North Western European one. Jews have also been accepted as being almost mainstream , but they will always be slightly different.
In the majority of northeastern USA, Italian Americans are perceived to be as equally white as any other white American. This also holds true for Portuguese Americans in the majority of the northeastern USA. The standards of whiteness in the USA is regional. You can't generalize the whole country as having the same standard of whiteness.