From what I can glean, the term ‘White Supremacist’ is a bit of a misnomer or generality. What they are really referring to is the Aryan Brotherhood a follow on group to the original Aryan Nation. These bad actors are in bed with one or more of the Mexican Drug Cartels.
It makes sense for them to hire local contracts for their dirty work.
The aryan brotherhood likely wouldn’t exist if liberals like the ACLU hadn’t insisted on desegregating the prisons and forced racial conflict among violent criminals.