The term is 'Native Americans' not 'Native United Staters'. White Southerners track their beginnings back to Europe. They have no more right to use the term than any other people who originated in Europe, Asia, or Africa.
How about this? "If they don't have the right to use the term ..... nobody does."
Anthropologists trace premodern Amerind genotypes to three migrations across the Bering Strait.
However, recent (last 15 years) excavations in both Americas suggest that the old Clovis "limit" of about 11,600 BP is fallacious, and that humans of another type were present for thousands of years before that, who were related to primitive Cromagnards who *appear* to have brought a type of Solutrean tool tradition across the North Atlantic pack-ice from pleniglacial Europe (following seabird migrations like the auk, it's speculated).
This primitive type is thought to have been a branch of the old Eurasian type that is now represented only by tiny remnants, such as the Ainu of Hokkaido, who differ(ed) substantially from later east Asian Mongoloid types.
If that inchoate recension of North American anthropological history is right, or somewhat right, then a) none of the North American populations extant or (like the Eurasian type) extinct can claim the name of autochthon, and b) the people who now claim to be "Native Americans" can do so only by blinking their ancestors' mass-murder and genocide (possibly cannibalistic!) of a predecessor population.