I mean, if anthropologists could definitely say that pre-Colombian clans were nomadic… maybe Mexico. But I would suggest the Mexican-American war may have settled the frontier and ended nomadic movement in, ya know, the 1840s. How absurd is that? Good grief.
Your rationale is 1000% more plausible…
Or this is just some local settling of scores, petty grievances or straight up klan racism under the cover of Trump’s insanity.